Hair & Nails

The Diagnosis: Allergic Contact Dermatitis

An allergic contact dermatitis (ACD) to acrylates was suspected and 4 patches were applied to the forearm (the North American Standard Series of the North American Contact Dermatitis Group). The patches were 2-hydroxyethyl methacrylate (2-HEMA) 2.0% permissible exposure limit (peL), ethyl acrylate 0.1% peL, tosylamide formaldehyde resin 10.0% peL, and methyl methacrylate 2.0% peL. A reading at 72 hours was performed and showed a positive reaction to hydroxyethyl methacrylate, ethyl acrylate, and methyl methacrylate, and a negative patch test to tosylamide formaldehyde resin (nail polish)(Figure). The patient was diagnosed with an allergic contact hypersensitivity to the aforementioned acrylates and instructed to avoid artificial nails and acrylate glues. She also was started on oral biotin supplements. On 6-month follow-up the patient had regrowth of all 10 fingernails without brittleness or splitting. She was able to use nail polishes but avoided all acrylic artificial nails and acrylate-containing personal care products.

Acrylate Allergy and Artificial Nails

Acrylates are plastic materials formed by polymerization of acrylic or methacrylic acid monomers and have been cited as a major cause of occupational and nonoccupational contact dermatitis. Contact dermatitis to acrylates in artificial nails was first reported in the 1950s.^1,2 Products containing 100% methyl methacrylate monomers in acrylic nails were banned by the US Food and Drug Administration in the early 1970s after receiving a number of complaints.³ However, no regulation prohibits the use of methyl methacrylate monomer in cosmetic products, and various methacrylate and acrylate monomers remain widely used.⁴ With a growing popularity in artificial nails, it is expected the number of sensitized persons will increase.

Acrylate allergy from sculptured nails concern self-curing resins made from a polymer powder and a liquid monomer solution. Advantages of new UV-cured products include the lack of unpleasant smell and simplified modeling. They also do not require an irritant, such as methacrylic acid, as a bonding agent. Instead, 2-HEMA and 2-hydroxypropyl methacrylate are added. These photobonded nails colloquially are called gel nails (acid free) as opposed to acrylic nails (using methacrylic acid as a primer). It is important to note that the esters of acrylic acid but not the acid itself sensitize patients, and sensitization is not caused by the uncured gel or the monomer solution but by the remaining monomers in the cured plastic nail and the dust filings that are produced during the finishing process.

Clinical Presentation

Symptoms of an ACD to nail acrylates include pruritus and fingertip dermatitis along with nail plate dystrophy. There may be pruritus at the nail base, with subsequent dryness, thickening, and onycholysis. The brittle nails may become split, discolored, and develop paronychia. Inadvertent contact with glue monomers or other acrylate-containing substances may cause eczematous lesions at distant sites. Avoidance of the allergen often results in complete restoration of the normal nail and fingertip within months.

Sensitization

Acrylates and methacrylates are ubiquitous materials used for both industrial and commercial applications. Due to their widespread industrial use, contact allergies to acrylates including 2-HEMA, 2-hydroxypropyl methacrylate, and triethyleneglycol diacrylate (TREGDA) are common. Cross-reaction of these compounds has been observed and is postulated to be due to reaction of the (meth)acrylate carboxyethyl group with the receptors of antigen-presenting cells.⁵ As a result, an individual with an acrylate allergy sensitized to one allergen often is allergic to its similar compounds and cross-reactors and must avoid the assortment of compounds containing these ingredients, which is important for individuals with occupational sensitization to a particular acrylate who is subsequently susceptible to other acrylate-containing compounds triggering allergic reactions when reexposure occurs in different settings.

Allergens and Occupational Exposure

Acrylates in cosmetic nail products are a source of ACD for not only the customer but also the manicurist.⁶ The most frequently cited sources of ACD in beauticians are acrylate chemicals.⁷ However, acrylate compounds are an occupational hazard for a number of other specialists, including dentists and dental technicians, histology technicians, and individuals in the printing industry.^8,9 Other individuals may be sensitized to acrylates through their inclusion in adhesives, dental bonding agents, hearing aids, electrocardiogram electrodes, artificial bone cement, and a myriad of other medical and nonmedical applications.^4,10-12 For workers who cannot avoid occupational exposure to these allergens, polyvinyl alcohol and multilayer laminate gloves are recommended, as natural rubber latex gloves do not always provide adequate protection from many of these agents.¹⁰

Testing for Suspected Acrylate Allergy

Cross-reactivity among acrylates is widely considered in the literature but remains enigmatic and is an important consideration with regard to routine patch test screening.¹³ In the case of an acrylate allergy to nail products, using 2-HEMA and ethylene glycol dimethacrylate is effective in detecting sensitization by photobonded nails and in patients sensitized by powder liquid products.¹⁴ One study showed a patch test panel including 2-HEMA, ethylene glycol dimethacrylate, and TREGDA was effective in identifying the majority of individuals with an allergy to acrylates in nail products and nail technicians.¹⁵ Another study has shown the most commonly positive testing allergens to be HEMA, ethyl acrylate, and methyl methacrylate.¹⁶ If one is patch testing only one chemical, it appears 2-HEMA is preferred.¹⁷ However, broader panels of screening allergens are necessary to achieve an accurate diagnosis. Furthermore, different panels of test allergens have been shown to vary in their ability to detect an acrylate allergy in different occupational exposures.¹² 

The time to patch test read also is important. A standard read at 72 hours is warranted; however, one study showed if only one read at day 3 was done without a subsequent day 7 read, then 25% of TREGDA and 50% of 2-HEMA allergies would have been missed in patients with occupational acrylate allergy.¹⁵ Other studies have reported late-appearing and long-lasting test reactions when testing for an acrylate allergy.^18,19 Clinicians should be cognizant that an acrylate allergy may be present even if initial screening is negative but the history and clinical picture are suggestive.

The Diagnosis: Allergic Contact Dermatitis

An allergic contact dermatitis (ACD) to acrylates was suspected and 4 patches were applied to the forearm (the North American Standard Series of the North American Contact Dermatitis Group). The patches were 2-hydroxyethyl methacrylate (2-HEMA) 2.0% permissible exposure limit (peL), ethyl acrylate 0.1% peL, tosylamide formaldehyde resin 10.0% peL, and methyl methacrylate 2.0% peL. A reading at 72 hours was performed and showed a positive reaction to hydroxyethyl methacrylate, ethyl acrylate, and methyl methacrylate, and a negative patch test to tosylamide formaldehyde resin (nail polish)(Figure). The patient was diagnosed with an allergic contact hypersensitivity to the aforementioned acrylates and instructed to avoid artificial nails and acrylate glues. She also was started on oral biotin supplements. On 6-month follow-up the patient had regrowth of all 10 fingernails without brittleness or splitting. She was able to use nail polishes but avoided all acrylic artificial nails and acrylate-containing personal care products.

Acrylate Allergy and Artificial Nails

Acrylates are plastic materials formed by polymerization of acrylic or methacrylic acid monomers and have been cited as a major cause of occupational and nonoccupational contact dermatitis. Contact dermatitis to acrylates in artificial nails was first reported in the 1950s.^1,2 Products containing 100% methyl methacrylate monomers in acrylic nails were banned by the US Food and Drug Administration in the early 1970s after receiving a number of complaints.³ However, no regulation prohibits the use of methyl methacrylate monomer in cosmetic products, and various methacrylate and acrylate monomers remain widely used.⁴ With a growing popularity in artificial nails, it is expected the number of sensitized persons will increase.

Acrylate allergy from sculptured nails concern self-curing resins made from a polymer powder and a liquid monomer solution. Advantages of new UV-cured products include the lack of unpleasant smell and simplified modeling. They also do not require an irritant, such as methacrylic acid, as a bonding agent. Instead, 2-HEMA and 2-hydroxypropyl methacrylate are added. These photobonded nails colloquially are called gel nails (acid free) as opposed to acrylic nails (using methacrylic acid as a primer). It is important to note that the esters of acrylic acid but not the acid itself sensitize patients, and sensitization is not caused by the uncured gel or the monomer solution but by the remaining monomers in the cured plastic nail and the dust filings that are produced during the finishing process.

Clinical Presentation

Symptoms of an ACD to nail acrylates include pruritus and fingertip dermatitis along with nail plate dystrophy. There may be pruritus at the nail base, with subsequent dryness, thickening, and onycholysis. The brittle nails may become split, discolored, and develop paronychia. Inadvertent contact with glue monomers or other acrylate-containing substances may cause eczematous lesions at distant sites. Avoidance of the allergen often results in complete restoration of the normal nail and fingertip within months.

Sensitization

Acrylates and methacrylates are ubiquitous materials used for both industrial and commercial applications. Due to their widespread industrial use, contact allergies to acrylates including 2-HEMA, 2-hydroxypropyl methacrylate, and triethyleneglycol diacrylate (TREGDA) are common. Cross-reaction of these compounds has been observed and is postulated to be due to reaction of the (meth)acrylate carboxyethyl group with the receptors of antigen-presenting cells.⁵ As a result, an individual with an acrylate allergy sensitized to one allergen often is allergic to its similar compounds and cross-reactors and must avoid the assortment of compounds containing these ingredients, which is important for individuals with occupational sensitization to a particular acrylate who is subsequently susceptible to other acrylate-containing compounds triggering allergic reactions when reexposure occurs in different settings.

Allergens and Occupational Exposure

Acrylates in cosmetic nail products are a source of ACD for not only the customer but also the manicurist.⁶ The most frequently cited sources of ACD in beauticians are acrylate chemicals.⁷ However, acrylate compounds are an occupational hazard for a number of other specialists, including dentists and dental technicians, histology technicians, and individuals in the printing industry.^8,9 Other individuals may be sensitized to acrylates through their inclusion in adhesives, dental bonding agents, hearing aids, electrocardiogram electrodes, artificial bone cement, and a myriad of other medical and nonmedical applications.^4,10-12 For workers who cannot avoid occupational exposure to these allergens, polyvinyl alcohol and multilayer laminate gloves are recommended, as natural rubber latex gloves do not always provide adequate protection from many of these agents.¹⁰

Testing for Suspected Acrylate Allergy

Cross-reactivity among acrylates is widely considered in the literature but remains enigmatic and is an important consideration with regard to routine patch test screening.¹³ In the case of an acrylate allergy to nail products, using 2-HEMA and ethylene glycol dimethacrylate is effective in detecting sensitization by photobonded nails and in patients sensitized by powder liquid products.¹⁴ One study showed a patch test panel including 2-HEMA, ethylene glycol dimethacrylate, and TREGDA was effective in identifying the majority of individuals with an allergy to acrylates in nail products and nail technicians.¹⁵ Another study has shown the most commonly positive testing allergens to be HEMA, ethyl acrylate, and methyl methacrylate.¹⁶ If one is patch testing only one chemical, it appears 2-HEMA is preferred.¹⁷ However, broader panels of screening allergens are necessary to achieve an accurate diagnosis. Furthermore, different panels of test allergens have been shown to vary in their ability to detect an acrylate allergy in different occupational exposures.¹² 

The time to patch test read also is important. A standard read at 72 hours is warranted; however, one study showed if only one read at day 3 was done without a subsequent day 7 read, then 25% of TREGDA and 50% of 2-HEMA allergies would have been missed in patients with occupational acrylate allergy.¹⁵ Other studies have reported late-appearing and long-lasting test reactions when testing for an acrylate allergy.^18,19 Clinicians should be cognizant that an acrylate allergy may be present even if initial screening is negative but the history and clinical picture are suggestive.

The Diagnosis: Allergic Contact Dermatitis

An allergic contact dermatitis (ACD) to acrylates was suspected and 4 patches were applied to the forearm (the North American Standard Series of the North American Contact Dermatitis Group). The patches were 2-hydroxyethyl methacrylate (2-HEMA) 2.0% permissible exposure limit (peL), ethyl acrylate 0.1% peL, tosylamide formaldehyde resin 10.0% peL, and methyl methacrylate 2.0% peL. A reading at 72 hours was performed and showed a positive reaction to hydroxyethyl methacrylate, ethyl acrylate, and methyl methacrylate, and a negative patch test to tosylamide formaldehyde resin (nail polish)(Figure). The patient was diagnosed with an allergic contact hypersensitivity to the aforementioned acrylates and instructed to avoid artificial nails and acrylate glues. She also was started on oral biotin supplements. On 6-month follow-up the patient had regrowth of all 10 fingernails without brittleness or splitting. She was able to use nail polishes but avoided all acrylic artificial nails and acrylate-containing personal care products.

Acrylate Allergy and Artificial Nails

Acrylates are plastic materials formed by polymerization of acrylic or methacrylic acid monomers and have been cited as a major cause of occupational and nonoccupational contact dermatitis. Contact dermatitis to acrylates in artificial nails was first reported in the 1950s.^1,2 Products containing 100% methyl methacrylate monomers in acrylic nails were banned by the US Food and Drug Administration in the early 1970s after receiving a number of complaints.³ However, no regulation prohibits the use of methyl methacrylate monomer in cosmetic products, and various methacrylate and acrylate monomers remain widely used.⁴ With a growing popularity in artificial nails, it is expected the number of sensitized persons will increase.

Acrylate allergy from sculptured nails concern self-curing resins made from a polymer powder and a liquid monomer solution. Advantages of new UV-cured products include the lack of unpleasant smell and simplified modeling. They also do not require an irritant, such as methacrylic acid, as a bonding agent. Instead, 2-HEMA and 2-hydroxypropyl methacrylate are added. These photobonded nails colloquially are called gel nails (acid free) as opposed to acrylic nails (using methacrylic acid as a primer). It is important to note that the esters of acrylic acid but not the acid itself sensitize patients, and sensitization is not caused by the uncured gel or the monomer solution but by the remaining monomers in the cured plastic nail and the dust filings that are produced during the finishing process.

Clinical Presentation

Symptoms of an ACD to nail acrylates include pruritus and fingertip dermatitis along with nail plate dystrophy. There may be pruritus at the nail base, with subsequent dryness, thickening, and onycholysis. The brittle nails may become split, discolored, and develop paronychia. Inadvertent contact with glue monomers or other acrylate-containing substances may cause eczematous lesions at distant sites. Avoidance of the allergen often results in complete restoration of the normal nail and fingertip within months.

Sensitization

Acrylates and methacrylates are ubiquitous materials used for both industrial and commercial applications. Due to their widespread industrial use, contact allergies to acrylates including 2-HEMA, 2-hydroxypropyl methacrylate, and triethyleneglycol diacrylate (TREGDA) are common. Cross-reaction of these compounds has been observed and is postulated to be due to reaction of the (meth)acrylate carboxyethyl group with the receptors of antigen-presenting cells.⁵ As a result, an individual with an acrylate allergy sensitized to one allergen often is allergic to its similar compounds and cross-reactors and must avoid the assortment of compounds containing these ingredients, which is important for individuals with occupational sensitization to a particular acrylate who is subsequently susceptible to other acrylate-containing compounds triggering allergic reactions when reexposure occurs in different settings.

Allergens and Occupational Exposure

Acrylates in cosmetic nail products are a source of ACD for not only the customer but also the manicurist.⁶ The most frequently cited sources of ACD in beauticians are acrylate chemicals.⁷ However, acrylate compounds are an occupational hazard for a number of other specialists, including dentists and dental technicians, histology technicians, and individuals in the printing industry.^8,9 Other individuals may be sensitized to acrylates through their inclusion in adhesives, dental bonding agents, hearing aids, electrocardiogram electrodes, artificial bone cement, and a myriad of other medical and nonmedical applications.^4,10-12 For workers who cannot avoid occupational exposure to these allergens, polyvinyl alcohol and multilayer laminate gloves are recommended, as natural rubber latex gloves do not always provide adequate protection from many of these agents.¹⁰

Testing for Suspected Acrylate Allergy

Cross-reactivity among acrylates is widely considered in the literature but remains enigmatic and is an important consideration with regard to routine patch test screening.¹³ In the case of an acrylate allergy to nail products, using 2-HEMA and ethylene glycol dimethacrylate is effective in detecting sensitization by photobonded nails and in patients sensitized by powder liquid products.¹⁴ One study showed a patch test panel including 2-HEMA, ethylene glycol dimethacrylate, and TREGDA was effective in identifying the majority of individuals with an allergy to acrylates in nail products and nail technicians.¹⁵ Another study has shown the most commonly positive testing allergens to be HEMA, ethyl acrylate, and methyl methacrylate.¹⁶ If one is patch testing only one chemical, it appears 2-HEMA is preferred.¹⁷ However, broader panels of screening allergens are necessary to achieve an accurate diagnosis. Furthermore, different panels of test allergens have been shown to vary in their ability to detect an acrylate allergy in different occupational exposures.¹² 

The time to patch test read also is important. A standard read at 72 hours is warranted; however, one study showed if only one read at day 3 was done without a subsequent day 7 read, then 25% of TREGDA and 50% of 2-HEMA allergies would have been missed in patients with occupational acrylate allergy.¹⁵ Other studies have reported late-appearing and long-lasting test reactions when testing for an acrylate allergy.^18,19 Clinicians should be cognizant that an acrylate allergy may be present even if initial screening is negative but the history and clinical picture are suggestive.

Adult patients who experience stress in the form of “anxiety sensitivity” are more likely to develop psychodermatological conditions than those that are not psychodermatological, a cross-sectional study of 115 participants shows.

“The results suggest that [anxiety sensitivity] interventions combined with dermatology treatments may be beneficial for psychodermatological patients,” wrote Laura J. Dixon, PhD, of the University of Mississippi Medical Center, Jackson, and her associates. “There is strong evidence that cognitive-behavioral therapy significantly reduces [anxiety sensitivity] through strategies such as psychoeducation, interoceptive exposure, and cognitive therapy.”

Dr. Dixon and her associates recruited 123 dermatologic patients aged 18-83 years over 30 weeks through three outpatient university dermatology clinics in Central Mississippi. Sixty-five percent of the participants were white, 33% were black, 1% were Asian, and 1% were Native American; 65% were female. Most of the patients were married and living with their spouses. The final sample of participants comprised 63 psychodermatological patients and 52 nonpsychodermatological patients (Psychosomatics. 2016;57:498-504).

The investigators assessed general anxiety symptoms using the 7-item depression, anxiety, and stress subscale (DASS-A) from the 21-item version of the questionnaire (DASS-21). Anxiety sensitivity – which refers to the “extent of beliefs that anxiety symptoms or arousal can have harmful consequences” (Turk Psikiyatri Derg. 2011 Fall;22[3]:187-93) – was measured using the Anxiety Sensitivity Index–3 (ASI-3, an 18-item self-report instrument that assesses physical manifestations of anxiety, such as blushing and fast heart beating.

Psychodermatological conditions were classified as disorders that might be rooted in or made worse by psychological, behavioral, or stress-related factors. Conditions in this category include acne, alopecia, atopic dermatitis, eczema, hidradenitis, prurigo, psoriasis, and rosacea. Dermatologic conditions not tied to psychological factors and classified as biologically based include brittle fingernails, cysts, keloids, rashes, skin cancer, skin lesions, spider veins, and warts, reported Dr. Dixon.

No significant differences were observed on the DASS-A scores between the two groups.

The mean scores of psychodermatological patients on the ASI-3 were significantly higher than the scores of patients with nonpsychodermatological conditions (21.1 vs. 13.7; P = .013). In fact, Dr. Dixon and her associates found that “each 1-unit increment in the ASI-3 social subscale score was associated with a 12.7% increased odds of patients having a psychodermatological condition.”

“Taken together, these results are supported by existing theoretical models of psychodermatological disorders that highlight the importance of stress among patients with certain dermatological conditions,” the researchers wrote.

One of the authors, dermatologist Robert T. Brodell, disclosed receiving honoraria from Allergan, Galderma Laboratories, and PharmaDerm; he also disclosed receiving consultant fees and performing clinical trials for other pharmaceutical companies. Neither Dr. Dixon nor any of the other authors declared relevant financial disclosures.

[email protected]

On Twitter @ginalhenderson

Adult patients who experience stress in the form of “anxiety sensitivity” are more likely to develop psychodermatological conditions than those that are not psychodermatological, a cross-sectional study of 115 participants shows.

“The results suggest that [anxiety sensitivity] interventions combined with dermatology treatments may be beneficial for psychodermatological patients,” wrote Laura J. Dixon, PhD, of the University of Mississippi Medical Center, Jackson, and her associates. “There is strong evidence that cognitive-behavioral therapy significantly reduces [anxiety sensitivity] through strategies such as psychoeducation, interoceptive exposure, and cognitive therapy.”

Dr. Dixon and her associates recruited 123 dermatologic patients aged 18-83 years over 30 weeks through three outpatient university dermatology clinics in Central Mississippi. Sixty-five percent of the participants were white, 33% were black, 1% were Asian, and 1% were Native American; 65% were female. Most of the patients were married and living with their spouses. The final sample of participants comprised 63 psychodermatological patients and 52 nonpsychodermatological patients (Psychosomatics. 2016;57:498-504).

The investigators assessed general anxiety symptoms using the 7-item depression, anxiety, and stress subscale (DASS-A) from the 21-item version of the questionnaire (DASS-21). Anxiety sensitivity – which refers to the “extent of beliefs that anxiety symptoms or arousal can have harmful consequences” (Turk Psikiyatri Derg. 2011 Fall;22[3]:187-93) – was measured using the Anxiety Sensitivity Index–3 (ASI-3, an 18-item self-report instrument that assesses physical manifestations of anxiety, such as blushing and fast heart beating.

Psychodermatological conditions were classified as disorders that might be rooted in or made worse by psychological, behavioral, or stress-related factors. Conditions in this category include acne, alopecia, atopic dermatitis, eczema, hidradenitis, prurigo, psoriasis, and rosacea. Dermatologic conditions not tied to psychological factors and classified as biologically based include brittle fingernails, cysts, keloids, rashes, skin cancer, skin lesions, spider veins, and warts, reported Dr. Dixon.

No significant differences were observed on the DASS-A scores between the two groups.

The mean scores of psychodermatological patients on the ASI-3 were significantly higher than the scores of patients with nonpsychodermatological conditions (21.1 vs. 13.7; P = .013). In fact, Dr. Dixon and her associates found that “each 1-unit increment in the ASI-3 social subscale score was associated with a 12.7% increased odds of patients having a psychodermatological condition.”

“Taken together, these results are supported by existing theoretical models of psychodermatological disorders that highlight the importance of stress among patients with certain dermatological conditions,” the researchers wrote.

One of the authors, dermatologist Robert T. Brodell, disclosed receiving honoraria from Allergan, Galderma Laboratories, and PharmaDerm; he also disclosed receiving consultant fees and performing clinical trials for other pharmaceutical companies. Neither Dr. Dixon nor any of the other authors declared relevant financial disclosures.

[email protected]

On Twitter @ginalhenderson

Adult patients who experience stress in the form of “anxiety sensitivity” are more likely to develop psychodermatological conditions than those that are not psychodermatological, a cross-sectional study of 115 participants shows.

“The results suggest that [anxiety sensitivity] interventions combined with dermatology treatments may be beneficial for psychodermatological patients,” wrote Laura J. Dixon, PhD, of the University of Mississippi Medical Center, Jackson, and her associates. “There is strong evidence that cognitive-behavioral therapy significantly reduces [anxiety sensitivity] through strategies such as psychoeducation, interoceptive exposure, and cognitive therapy.”

Dr. Dixon and her associates recruited 123 dermatologic patients aged 18-83 years over 30 weeks through three outpatient university dermatology clinics in Central Mississippi. Sixty-five percent of the participants were white, 33% were black, 1% were Asian, and 1% were Native American; 65% were female. Most of the patients were married and living with their spouses. The final sample of participants comprised 63 psychodermatological patients and 52 nonpsychodermatological patients (Psychosomatics. 2016;57:498-504).

The investigators assessed general anxiety symptoms using the 7-item depression, anxiety, and stress subscale (DASS-A) from the 21-item version of the questionnaire (DASS-21). Anxiety sensitivity – which refers to the “extent of beliefs that anxiety symptoms or arousal can have harmful consequences” (Turk Psikiyatri Derg. 2011 Fall;22[3]:187-93) – was measured using the Anxiety Sensitivity Index–3 (ASI-3, an 18-item self-report instrument that assesses physical manifestations of anxiety, such as blushing and fast heart beating.

Psychodermatological conditions were classified as disorders that might be rooted in or made worse by psychological, behavioral, or stress-related factors. Conditions in this category include acne, alopecia, atopic dermatitis, eczema, hidradenitis, prurigo, psoriasis, and rosacea. Dermatologic conditions not tied to psychological factors and classified as biologically based include brittle fingernails, cysts, keloids, rashes, skin cancer, skin lesions, spider veins, and warts, reported Dr. Dixon.

No significant differences were observed on the DASS-A scores between the two groups.

The mean scores of psychodermatological patients on the ASI-3 were significantly higher than the scores of patients with nonpsychodermatological conditions (21.1 vs. 13.7; P = .013). In fact, Dr. Dixon and her associates found that “each 1-unit increment in the ASI-3 social subscale score was associated with a 12.7% increased odds of patients having a psychodermatological condition.”

“Taken together, these results are supported by existing theoretical models of psychodermatological disorders that highlight the importance of stress among patients with certain dermatological conditions,” the researchers wrote.

One of the authors, dermatologist Robert T. Brodell, disclosed receiving honoraria from Allergan, Galderma Laboratories, and PharmaDerm; he also disclosed receiving consultant fees and performing clinical trials for other pharmaceutical companies. Neither Dr. Dixon nor any of the other authors declared relevant financial disclosures.

[email protected]

On Twitter @ginalhenderson

Onychomadesis is an acute, noninflammatory, painless, proximal separation of the nail plate from the nail matrix. It occurs due to an abrupt stoppage of nail production by matrix cells, producing temporary cessation of nail growth with or without subsequent complete shedding of nails.^1-10 Onychomadesis has a wide spectrum of clinical presentations ranging from mild transverse ridges of the nail plate (Beau lines) to complete nail shedding.^4,11 Onychomadesis may be related to systemic and dermatologic diseases, drugs (eg, chemotherapeutic agents, anticonvulsants, lithium, retinoids), nail trauma, fever, or infection,⁵ and a connection between onychomadesis and hand-foot-and-mouth disease (HFMD) was first described by Clementz et al¹² following outbreaks in Europe, Asia, and the United States.

Epidemiology

Onychomadesis has been observed in children of all ages including neonates. Neonatal onychomadesis is thought to be related to perinatal stressors and birth trauma, with possible exacerbation by superimposed candidiasis.¹⁰ Depending on the underlying cause, there may be involvement of a single nail or multiple nails. Nag et al¹ noted that onychomadesis was most commonly observed in nails of the middle finger (73.7%), followed by the thumb (63.2%) and ring finger (52.6%). Fingernails are more commonly involved than toenails.¹

Clementz et al¹² first proposed the association between onychomadesis and HFMD in 2000. Patients with a history of HFMD were found to be 14 times more likely to develop onychomadesis (relative risk, 14; 95% confidence interval, 4.57-42.86).⁴ A common pathogen for HFMD is coxsackievirus A6 (CVA6),^13,14 but the mechanism of onychomadesis in HFMD remains unclear.^5,7,13 Outbreaks of HFMD have been reported in Spain, Finland, Japan, Thailand, the United States, Singapore, and China.¹⁵ During an outbreak of HFMD in Taiwan, the incidence of onychomadesis following CVA6 infection was 37% (48/130) compared to 5% (7/145) in cases with non-CVA6 causative strains.¹⁶ There also have been observed differences in the prevalence of onychomadesis by age: a 55% (18/33) occurrence rate was noted in the youngest age group (range, 9–23 months), 30% (8/27) in the middle age group (range, 24–32 months), and 4% (1/28) in the oldest age group (range, 33–42 months), with an average of 4 nails shed per case.¹⁷ A study in Spain also found a high occurrence of onychomadesis in a nursery setting, with 92% (11/12) of onychomadesis cases preceded by HFMD 2 months prior.¹⁸

Etiology

Local trauma to the nail bed is the most common cause of single-digit onychomadesis.⁴ Multiple-digit involvement suggests a systemic etiology such as fever, erythroderma, and Kawasaki disease; use of drugs (eg, chemotherapeutic agents, anticonvulsants, lithium, retinoids); and viral infections such as HFMD and varicella at the infantile age (Table).^5,9,19 Most drug-related nail changes are the outcome of acute toxicity to the proliferating nail matrix epithelium. If onychomadesis affects all nails at the same level, the patient’s history of medication use and other treatments taken 2 to 3 weeks prior to the appearance of the nail findings should be evaluated. Chemotherapeutic agents produce nail changes in a high proportion of patients, which often are related to drug dosage. These effects also are reproducible with re-administration of the drug.²⁰ Onychomadesis also has been reported as a possible side effect of anticonvulsants such as valproic acid (VPA).²¹ One study evaluating the link between VPA and onychomadesis indicated that nail changes may be due to a disturbance of zinc metabolism.²² However, the pathomechanism of onychomadesis associated with VPA treatment remains unclear.²¹ Onychomadesis also has developed after an allergic drug reaction to oral penicillin V after treatment of a sore throat in a 23-month-old child.²³

Nail involvement has been reported in 10% of cases of inflammatory conditions such as lichen planus²¹; however, it may be more common but underrecognized and underreported. Grover et al⁹ indicated that lichen planus–induced severe inflammation in the matrix of the nail unit leading to a temporary growth arrest was the possible mechanism leading to nail shedding. Prompt systemic and intramatricial steroid treatment of lichen planus is required to avoid potential scarring of the nail matrix and permanent damage.⁹

Onychomadesis also has been reported following varicella infection (chickenpox). Podder et al¹⁹ reported the case of a 7-year-old girl who had recovered from a varicella infection 5 weeks prior and presented with onychomadesis of the right index fingernail with all other fingernails and toenails appearing normal. Kocak and Koçak⁵ reported onychomadesis in 2 sisters with varicella infection. There are few reported cases, so it is still unclear whether varicella infection is an inciting factor.¹⁹

One of the most studied viral infections linked to onychomadesis is HFMD, which is a common viral infection that mostly affects children younger than 10 years.¹ The precise mechanism of onychomadesis for these viral infection events remains unclear.^7,10,13 Several theories have been delineated, including nail matrix arrest from fever occurring during HFMD.⁶ However, this cause is unlikely, as fevers are typically low grade and present only for a few hours.^4,6,13 Direct inflammation spreading from skin lesions of HFMD around the nails or maceration associated with finger blisters could cause onychomadesis.^1,5,7 Haneke²⁴ hypothesized that nail shedding may be the consequence of vesicles localized in the periungual tissue, but studies have shown incidence without prior lesions on the fingers and no relationship between nail matrix arrest and severity of HFMD.^5,6,13 Bettoli et al²⁵ reported that inflammation secondary to viral infection around the nail matrix might be induced directly by viruses or indirectly by virus-specific immunocomplexes and consequent distal embolism. Osterback et al¹⁴ used reverse transcription–polymerase chain reaction to detect CVA6 in fragmented nails from 2 children and 1 parent following an HFMD episode, suggesting that virus replication could damage the nail matrix, resulting in onychomadesis. Cabrerizo et al¹⁸ also suggested that virus replication directly damages the nail matrix based on the presence of CVA6 in shed nails. Because fingernails with onychomadesis are not always of the fingers affected by HFMD, an indirect effect of viral infection on the nail matrix is more plausible.⁸ Additional studies are needed to clarify the virus-associated mechanism of nail matrix arrest.⁶ Finally, frequent washing of hands¹⁵ resulting in maceration, Candida infection, and allergic contact dermatitis² may be possible causes. It is unclear if onychomadesis following HFMD is related to viral replication, inflammation, or intensive hygienic measures, and further investigation is needed.^2,15

Clinical Characteristics

The ventral floor is the site of the germinal matrix and is responsible for 90% of nail production. As a result, more of the nail plate substance is produced proximally, leading to a natural convex curvature from the proximal to distal nail.¹¹ Beau lines are transverse ridging of the nail plates.⁶ Onychomadesis may be viewed as a more severe form of Beau lines, with complete separation and possible shedding of the nail plate (Figure).^3,4 In both cases, an insult to the nail matrix is followed by recovery and production of the nail plate at the nail matrix.⁴ In Beau lines, slowing or disruption of cell growth from the proximal matrix results in a thinner nail plate, leading to transverse depressions. Onychomadesis has a similar pathophysiology but is associated with a complete halt in the nail plate production.³

Diagnosis

The diagnosis of onychomadesis is made clinically.^3,10 Distinct nail changes can be detected by inspection and palpation of the nail plate,^3,11 which allows for differentiation between Beau lines and complete nail shedding. Additionally, any signs of nail trauma need to be noted, as well as pain, swelling, or pruritus, as these symptoms also can guide in determining the etiology of the nail dystrophy. Ultrasonography can confirm the diagnosis, as the defect can be identified beneath the proximal nail fold.^3,26 When it occurs after HFMD or varicella, onychomadesis tends to present in 28 to 40 days following infection.^4,6,10 Physicians should consider underlying associations. A review of viral illnesses within 1 to 2 months prior to development of nail changes often will identify the causative disease.⁴ Each patient should be evaluated for recent nail trauma; medications; viral infection; and autoimmune, systemic, and inflammatory diseases.

Treatment

Onychomadesis typically is mild and self-limited.^4,10 There is no specific treatment,¹⁰ but a conservative approach to management is recommended. Treatment of any underlying medical conditions or discontinuation of an offending medication may help to prevent recurrent onychomadesis.³ Supportive care along with protection of the nail bed by maintaining short nails and using adhesive bandages over the affected nails to avoid snagging the nail or ripping off the partially attached nails is recommended.⁴ In some cases, onychomadesis has been treated with topical application of urea cream 40% under occlusion²⁷ or halcinonide cream 0.1% under occlusion for 5 to 6 days,²⁸ but these treatments have not been universally effective.³ External use of basic fibroblast growth factor to stimulate new regrowth of the nail plate has been advocated.³ It is important to reassure patients that as long as the underlying causes are eliminated and the nail matrix has not been permanently scarred, the nails should grow back within 12 weeks or sooner in children. Thus, typically only reassurance and counseling of parents/guardians is required for onychomadesis in children.^1,2 However, the nails may be dystrophic or fail to regrow if there is poor peripheral circulation or permanent nail matrix damage.

Conclusion

Fortunately, onychomadesis is self-limited. Physicians should look for underlying causes of onychomadesis, including a history of viral infections such as HFMD and varicella as well as systemic diseases and use of medications. As long as any underlying disorder or condition has been resolved, spontaneous regrowth of healthy nails usually but not always occurs within 12 weeks or sooner in children.

Onychomadesis is an acute, noninflammatory, painless, proximal separation of the nail plate from the nail matrix. It occurs due to an abrupt stoppage of nail production by matrix cells, producing temporary cessation of nail growth with or without subsequent complete shedding of nails.^1-10 Onychomadesis has a wide spectrum of clinical presentations ranging from mild transverse ridges of the nail plate (Beau lines) to complete nail shedding.^4,11 Onychomadesis may be related to systemic and dermatologic diseases, drugs (eg, chemotherapeutic agents, anticonvulsants, lithium, retinoids), nail trauma, fever, or infection,⁵ and a connection between onychomadesis and hand-foot-and-mouth disease (HFMD) was first described by Clementz et al¹² following outbreaks in Europe, Asia, and the United States.

Epidemiology

Onychomadesis has been observed in children of all ages including neonates. Neonatal onychomadesis is thought to be related to perinatal stressors and birth trauma, with possible exacerbation by superimposed candidiasis.¹⁰ Depending on the underlying cause, there may be involvement of a single nail or multiple nails. Nag et al¹ noted that onychomadesis was most commonly observed in nails of the middle finger (73.7%), followed by the thumb (63.2%) and ring finger (52.6%). Fingernails are more commonly involved than toenails.¹

Clementz et al¹² first proposed the association between onychomadesis and HFMD in 2000. Patients with a history of HFMD were found to be 14 times more likely to develop onychomadesis (relative risk, 14; 95% confidence interval, 4.57-42.86).⁴ A common pathogen for HFMD is coxsackievirus A6 (CVA6),^13,14 but the mechanism of onychomadesis in HFMD remains unclear.^5,7,13 Outbreaks of HFMD have been reported in Spain, Finland, Japan, Thailand, the United States, Singapore, and China.¹⁵ During an outbreak of HFMD in Taiwan, the incidence of onychomadesis following CVA6 infection was 37% (48/130) compared to 5% (7/145) in cases with non-CVA6 causative strains.¹⁶ There also have been observed differences in the prevalence of onychomadesis by age: a 55% (18/33) occurrence rate was noted in the youngest age group (range, 9–23 months), 30% (8/27) in the middle age group (range, 24–32 months), and 4% (1/28) in the oldest age group (range, 33–42 months), with an average of 4 nails shed per case.¹⁷ A study in Spain also found a high occurrence of onychomadesis in a nursery setting, with 92% (11/12) of onychomadesis cases preceded by HFMD 2 months prior.¹⁸

Etiology

Local trauma to the nail bed is the most common cause of single-digit onychomadesis.⁴ Multiple-digit involvement suggests a systemic etiology such as fever, erythroderma, and Kawasaki disease; use of drugs (eg, chemotherapeutic agents, anticonvulsants, lithium, retinoids); and viral infections such as HFMD and varicella at the infantile age (Table).^5,9,19 Most drug-related nail changes are the outcome of acute toxicity to the proliferating nail matrix epithelium. If onychomadesis affects all nails at the same level, the patient’s history of medication use and other treatments taken 2 to 3 weeks prior to the appearance of the nail findings should be evaluated. Chemotherapeutic agents produce nail changes in a high proportion of patients, which often are related to drug dosage. These effects also are reproducible with re-administration of the drug.²⁰ Onychomadesis also has been reported as a possible side effect of anticonvulsants such as valproic acid (VPA).²¹ One study evaluating the link between VPA and onychomadesis indicated that nail changes may be due to a disturbance of zinc metabolism.²² However, the pathomechanism of onychomadesis associated with VPA treatment remains unclear.²¹ Onychomadesis also has developed after an allergic drug reaction to oral penicillin V after treatment of a sore throat in a 23-month-old child.²³

Nail involvement has been reported in 10% of cases of inflammatory conditions such as lichen planus²¹; however, it may be more common but underrecognized and underreported. Grover et al⁹ indicated that lichen planus–induced severe inflammation in the matrix of the nail unit leading to a temporary growth arrest was the possible mechanism leading to nail shedding. Prompt systemic and intramatricial steroid treatment of lichen planus is required to avoid potential scarring of the nail matrix and permanent damage.⁹

Onychomadesis also has been reported following varicella infection (chickenpox). Podder et al¹⁹ reported the case of a 7-year-old girl who had recovered from a varicella infection 5 weeks prior and presented with onychomadesis of the right index fingernail with all other fingernails and toenails appearing normal. Kocak and Koçak⁵ reported onychomadesis in 2 sisters with varicella infection. There are few reported cases, so it is still unclear whether varicella infection is an inciting factor.¹⁹

One of the most studied viral infections linked to onychomadesis is HFMD, which is a common viral infection that mostly affects children younger than 10 years.¹ The precise mechanism of onychomadesis for these viral infection events remains unclear.^7,10,13 Several theories have been delineated, including nail matrix arrest from fever occurring during HFMD.⁶ However, this cause is unlikely, as fevers are typically low grade and present only for a few hours.^4,6,13 Direct inflammation spreading from skin lesions of HFMD around the nails or maceration associated with finger blisters could cause onychomadesis.^1,5,7 Haneke²⁴ hypothesized that nail shedding may be the consequence of vesicles localized in the periungual tissue, but studies have shown incidence without prior lesions on the fingers and no relationship between nail matrix arrest and severity of HFMD.^5,6,13 Bettoli et al²⁵ reported that inflammation secondary to viral infection around the nail matrix might be induced directly by viruses or indirectly by virus-specific immunocomplexes and consequent distal embolism. Osterback et al¹⁴ used reverse transcription–polymerase chain reaction to detect CVA6 in fragmented nails from 2 children and 1 parent following an HFMD episode, suggesting that virus replication could damage the nail matrix, resulting in onychomadesis. Cabrerizo et al¹⁸ also suggested that virus replication directly damages the nail matrix based on the presence of CVA6 in shed nails. Because fingernails with onychomadesis are not always of the fingers affected by HFMD, an indirect effect of viral infection on the nail matrix is more plausible.⁸ Additional studies are needed to clarify the virus-associated mechanism of nail matrix arrest.⁶ Finally, frequent washing of hands¹⁵ resulting in maceration, Candida infection, and allergic contact dermatitis² may be possible causes. It is unclear if onychomadesis following HFMD is related to viral replication, inflammation, or intensive hygienic measures, and further investigation is needed.^2,15

Clinical Characteristics

The ventral floor is the site of the germinal matrix and is responsible for 90% of nail production. As a result, more of the nail plate substance is produced proximally, leading to a natural convex curvature from the proximal to distal nail.¹¹ Beau lines are transverse ridging of the nail plates.⁶ Onychomadesis may be viewed as a more severe form of Beau lines, with complete separation and possible shedding of the nail plate (Figure).^3,4 In both cases, an insult to the nail matrix is followed by recovery and production of the nail plate at the nail matrix.⁴ In Beau lines, slowing or disruption of cell growth from the proximal matrix results in a thinner nail plate, leading to transverse depressions. Onychomadesis has a similar pathophysiology but is associated with a complete halt in the nail plate production.³

Diagnosis

The diagnosis of onychomadesis is made clinically.^3,10 Distinct nail changes can be detected by inspection and palpation of the nail plate,^3,11 which allows for differentiation between Beau lines and complete nail shedding. Additionally, any signs of nail trauma need to be noted, as well as pain, swelling, or pruritus, as these symptoms also can guide in determining the etiology of the nail dystrophy. Ultrasonography can confirm the diagnosis, as the defect can be identified beneath the proximal nail fold.^3,26 When it occurs after HFMD or varicella, onychomadesis tends to present in 28 to 40 days following infection.^4,6,10 Physicians should consider underlying associations. A review of viral illnesses within 1 to 2 months prior to development of nail changes often will identify the causative disease.⁴ Each patient should be evaluated for recent nail trauma; medications; viral infection; and autoimmune, systemic, and inflammatory diseases.

Treatment

Onychomadesis typically is mild and self-limited.^4,10 There is no specific treatment,¹⁰ but a conservative approach to management is recommended. Treatment of any underlying medical conditions or discontinuation of an offending medication may help to prevent recurrent onychomadesis.³ Supportive care along with protection of the nail bed by maintaining short nails and using adhesive bandages over the affected nails to avoid snagging the nail or ripping off the partially attached nails is recommended.⁴ In some cases, onychomadesis has been treated with topical application of urea cream 40% under occlusion²⁷ or halcinonide cream 0.1% under occlusion for 5 to 6 days,²⁸ but these treatments have not been universally effective.³ External use of basic fibroblast growth factor to stimulate new regrowth of the nail plate has been advocated.³ It is important to reassure patients that as long as the underlying causes are eliminated and the nail matrix has not been permanently scarred, the nails should grow back within 12 weeks or sooner in children. Thus, typically only reassurance and counseling of parents/guardians is required for onychomadesis in children.^1,2 However, the nails may be dystrophic or fail to regrow if there is poor peripheral circulation or permanent nail matrix damage.

Conclusion

Fortunately, onychomadesis is self-limited. Physicians should look for underlying causes of onychomadesis, including a history of viral infections such as HFMD and varicella as well as systemic diseases and use of medications. As long as any underlying disorder or condition has been resolved, spontaneous regrowth of healthy nails usually but not always occurs within 12 weeks or sooner in children.

Onychomadesis is an acute, noninflammatory, painless, proximal separation of the nail plate from the nail matrix. It occurs due to an abrupt stoppage of nail production by matrix cells, producing temporary cessation of nail growth with or without subsequent complete shedding of nails.^1-10 Onychomadesis has a wide spectrum of clinical presentations ranging from mild transverse ridges of the nail plate (Beau lines) to complete nail shedding.^4,11 Onychomadesis may be related to systemic and dermatologic diseases, drugs (eg, chemotherapeutic agents, anticonvulsants, lithium, retinoids), nail trauma, fever, or infection,⁵ and a connection between onychomadesis and hand-foot-and-mouth disease (HFMD) was first described by Clementz et al¹² following outbreaks in Europe, Asia, and the United States.

Epidemiology

Onychomadesis has been observed in children of all ages including neonates. Neonatal onychomadesis is thought to be related to perinatal stressors and birth trauma, with possible exacerbation by superimposed candidiasis.¹⁰ Depending on the underlying cause, there may be involvement of a single nail or multiple nails. Nag et al¹ noted that onychomadesis was most commonly observed in nails of the middle finger (73.7%), followed by the thumb (63.2%) and ring finger (52.6%). Fingernails are more commonly involved than toenails.¹

Clementz et al¹² first proposed the association between onychomadesis and HFMD in 2000. Patients with a history of HFMD were found to be 14 times more likely to develop onychomadesis (relative risk, 14; 95% confidence interval, 4.57-42.86).⁴ A common pathogen for HFMD is coxsackievirus A6 (CVA6),^13,14 but the mechanism of onychomadesis in HFMD remains unclear.^5,7,13 Outbreaks of HFMD have been reported in Spain, Finland, Japan, Thailand, the United States, Singapore, and China.¹⁵ During an outbreak of HFMD in Taiwan, the incidence of onychomadesis following CVA6 infection was 37% (48/130) compared to 5% (7/145) in cases with non-CVA6 causative strains.¹⁶ There also have been observed differences in the prevalence of onychomadesis by age: a 55% (18/33) occurrence rate was noted in the youngest age group (range, 9–23 months), 30% (8/27) in the middle age group (range, 24–32 months), and 4% (1/28) in the oldest age group (range, 33–42 months), with an average of 4 nails shed per case.¹⁷ A study in Spain also found a high occurrence of onychomadesis in a nursery setting, with 92% (11/12) of onychomadesis cases preceded by HFMD 2 months prior.¹⁸

Etiology

Local trauma to the nail bed is the most common cause of single-digit onychomadesis.⁴ Multiple-digit involvement suggests a systemic etiology such as fever, erythroderma, and Kawasaki disease; use of drugs (eg, chemotherapeutic agents, anticonvulsants, lithium, retinoids); and viral infections such as HFMD and varicella at the infantile age (Table).^5,9,19 Most drug-related nail changes are the outcome of acute toxicity to the proliferating nail matrix epithelium. If onychomadesis affects all nails at the same level, the patient’s history of medication use and other treatments taken 2 to 3 weeks prior to the appearance of the nail findings should be evaluated. Chemotherapeutic agents produce nail changes in a high proportion of patients, which often are related to drug dosage. These effects also are reproducible with re-administration of the drug.²⁰ Onychomadesis also has been reported as a possible side effect of anticonvulsants such as valproic acid (VPA).²¹ One study evaluating the link between VPA and onychomadesis indicated that nail changes may be due to a disturbance of zinc metabolism.²² However, the pathomechanism of onychomadesis associated with VPA treatment remains unclear.²¹ Onychomadesis also has developed after an allergic drug reaction to oral penicillin V after treatment of a sore throat in a 23-month-old child.²³

Nail involvement has been reported in 10% of cases of inflammatory conditions such as lichen planus²¹; however, it may be more common but underrecognized and underreported. Grover et al⁹ indicated that lichen planus–induced severe inflammation in the matrix of the nail unit leading to a temporary growth arrest was the possible mechanism leading to nail shedding. Prompt systemic and intramatricial steroid treatment of lichen planus is required to avoid potential scarring of the nail matrix and permanent damage.⁹

Onychomadesis also has been reported following varicella infection (chickenpox). Podder et al¹⁹ reported the case of a 7-year-old girl who had recovered from a varicella infection 5 weeks prior and presented with onychomadesis of the right index fingernail with all other fingernails and toenails appearing normal. Kocak and Koçak⁵ reported onychomadesis in 2 sisters with varicella infection. There are few reported cases, so it is still unclear whether varicella infection is an inciting factor.¹⁹

One of the most studied viral infections linked to onychomadesis is HFMD, which is a common viral infection that mostly affects children younger than 10 years.¹ The precise mechanism of onychomadesis for these viral infection events remains unclear.^7,10,13 Several theories have been delineated, including nail matrix arrest from fever occurring during HFMD.⁶ However, this cause is unlikely, as fevers are typically low grade and present only for a few hours.^4,6,13 Direct inflammation spreading from skin lesions of HFMD around the nails or maceration associated with finger blisters could cause onychomadesis.^1,5,7 Haneke²⁴ hypothesized that nail shedding may be the consequence of vesicles localized in the periungual tissue, but studies have shown incidence without prior lesions on the fingers and no relationship between nail matrix arrest and severity of HFMD.^5,6,13 Bettoli et al²⁵ reported that inflammation secondary to viral infection around the nail matrix might be induced directly by viruses or indirectly by virus-specific immunocomplexes and consequent distal embolism. Osterback et al¹⁴ used reverse transcription–polymerase chain reaction to detect CVA6 in fragmented nails from 2 children and 1 parent following an HFMD episode, suggesting that virus replication could damage the nail matrix, resulting in onychomadesis. Cabrerizo et al¹⁸ also suggested that virus replication directly damages the nail matrix based on the presence of CVA6 in shed nails. Because fingernails with onychomadesis are not always of the fingers affected by HFMD, an indirect effect of viral infection on the nail matrix is more plausible.⁸ Additional studies are needed to clarify the virus-associated mechanism of nail matrix arrest.⁶ Finally, frequent washing of hands¹⁵ resulting in maceration, Candida infection, and allergic contact dermatitis² may be possible causes. It is unclear if onychomadesis following HFMD is related to viral replication, inflammation, or intensive hygienic measures, and further investigation is needed.^2,15

Clinical Characteristics

The ventral floor is the site of the germinal matrix and is responsible for 90% of nail production. As a result, more of the nail plate substance is produced proximally, leading to a natural convex curvature from the proximal to distal nail.¹¹ Beau lines are transverse ridging of the nail plates.⁶ Onychomadesis may be viewed as a more severe form of Beau lines, with complete separation and possible shedding of the nail plate (Figure).^3,4 In both cases, an insult to the nail matrix is followed by recovery and production of the nail plate at the nail matrix.⁴ In Beau lines, slowing or disruption of cell growth from the proximal matrix results in a thinner nail plate, leading to transverse depressions. Onychomadesis has a similar pathophysiology but is associated with a complete halt in the nail plate production.³

Diagnosis

The diagnosis of onychomadesis is made clinically.^3,10 Distinct nail changes can be detected by inspection and palpation of the nail plate,^3,11 which allows for differentiation between Beau lines and complete nail shedding. Additionally, any signs of nail trauma need to be noted, as well as pain, swelling, or pruritus, as these symptoms also can guide in determining the etiology of the nail dystrophy. Ultrasonography can confirm the diagnosis, as the defect can be identified beneath the proximal nail fold.^3,26 When it occurs after HFMD or varicella, onychomadesis tends to present in 28 to 40 days following infection.^4,6,10 Physicians should consider underlying associations. A review of viral illnesses within 1 to 2 months prior to development of nail changes often will identify the causative disease.⁴ Each patient should be evaluated for recent nail trauma; medications; viral infection; and autoimmune, systemic, and inflammatory diseases.

Treatment

Onychomadesis typically is mild and self-limited.^4,10 There is no specific treatment,¹⁰ but a conservative approach to management is recommended. Treatment of any underlying medical conditions or discontinuation of an offending medication may help to prevent recurrent onychomadesis.³ Supportive care along with protection of the nail bed by maintaining short nails and using adhesive bandages over the affected nails to avoid snagging the nail or ripping off the partially attached nails is recommended.⁴ In some cases, onychomadesis has been treated with topical application of urea cream 40% under occlusion²⁷ or halcinonide cream 0.1% under occlusion for 5 to 6 days,²⁸ but these treatments have not been universally effective.³ External use of basic fibroblast growth factor to stimulate new regrowth of the nail plate has been advocated.³ It is important to reassure patients that as long as the underlying causes are eliminated and the nail matrix has not been permanently scarred, the nails should grow back within 12 weeks or sooner in children. Thus, typically only reassurance and counseling of parents/guardians is required for onychomadesis in children.^1,2 However, the nails may be dystrophic or fail to regrow if there is poor peripheral circulation or permanent nail matrix damage.

Conclusion

Fortunately, onychomadesis is self-limited. Physicians should look for underlying causes of onychomadesis, including a history of viral infections such as HFMD and varicella as well as systemic diseases and use of medications. As long as any underlying disorder or condition has been resolved, spontaneous regrowth of healthy nails usually but not always occurs within 12 weeks or sooner in children.

Review the PDF of the fact sheet on common hair disorders with board-relevant, easy-to-review material. This fact sheet reviews information about the most common hair disorders, including clinical and histopathological features, trichoscopy, and management of these diseases.

Practice Questions

1. A 40-year-old woman presents to the clinic with a burning sensation and tenderness on the scalp. At physical examination you notice erythematous papules and pustules on the vertex scalp. The most likely diagnosis is:

a. alopecia areata
b. CCSA
c. folliculitis decalvans
d. lichen planopilaris
e. traction alopecia

2. A 60-year-old woman presents with receding hair loss on the frontal and bitemporal scalp. She has noticed hair loss on her eyebrows. She has a history of oral ulcers. On physical examination there is mild erythema and perifollicular scales on the frontal hairline. A hair pull test is positive in this area. The most likely diagnosis is:

a. androgenetic alopecia
b. chronic cutaneous lupus erythematosus
c. frontal fibrosing alopecia
d. telogen effluvium
e. trichotillomania

3. A 5-year-old girl with a history of seasonal allergies and eczema presents with recurrent patchy hair loss on the scalp of 6 months’ duration. Her mother has noticed rapidly progressive hair loss affecting the whole scalp. On trichoscopy, you find yellow dots, broken hairs, and tapering hairs. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. telogen effluvium
d. traction alopecia
e. trichotillomania

4. A 30-year-old white woman with history of obsessive-compulsive disorder presents to the clinic with hair loss for the last 3 years. She says she has noticed worsening of the hair loss when she is under stress. She also bites her nails. On physical examination you identify an irregular patch of alopecia with broken hairs on the occipital scalp. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. lichen planopilaris
d. traction alopecia
e. trichotillomania

5. A 45-year-old black woman who has a family history of hair loss in her mother presents with tenderness and burning sensation on the vertex scalp. She reports the hair loss was worse after she got a hair relaxer 6 months prior. She uses braids on her scalp and she has not had a relaxer since then. The most likely diagnosis is:

a. CCSA
b. chronic cutaneous lupus erythematosus
c. folliculitis decalvans
d. lichen planopilaris
e. trichotillomania

Answers to practice questions provided on next page

Practice Question Answers

1. A 40-year-old woman presents to the clinic with a burning sensation and tenderness on the scalp. At physical examination you notice erythematous papules and pustules on the vertex scalp. The most likely diagnosis is:

a. alopecia areata
b. CCSA
c. folliculitis decalvans
d. lichen planopilaris
e. traction alopecia

2. A 60-year-old woman presents with receding hair loss on the frontal and bitemporal scalp. She has noticed hair loss on her eyebrows. She has a history of oral ulcers. On physical examination there is mild erythema and perifollicular scales on the frontal hairline. A hair pull test is positive in this area. The most likely diagnosis is:

a. androgenetic alopecia
b. chronic cutaneous lupus erythematosus
c. frontal fibrosing alopecia
d. telogen effluvium
e. trichotillomania

3. A 5-year-old girl with a history of seasonal allergies and eczema presents with recurrent patchy hair loss on the scalp of 6 months’ duration. Her mother has noticed rapidly progressive hair loss affecting the whole scalp. On trichoscopy, you find yellow dots, broken hairs, and tapering hairs. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. telogen effluvium
d. traction alopecia
e. trichotillomania

4. A 30-year-old white woman with history of obsessive-compulsive disorder presents to the clinic with hair loss for the last 3 years. She says she has noticed worsening of the hair loss when she is under stress. She also bites her nails. On physical examination you identify an irregular patch of alopecia with broken hairs on the occipital scalp. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. lichen planopilaris
d. traction alopecia
e. trichotillomania

5. A 45-year-old black woman who has a family history of hair loss in her mother presents with tenderness and burning sensation on the vertex scalp. She reports the hair loss was worse after she got a hair relaxer 6 months prior. She uses braids on her scalp and she has not had a relaxer since then. The most likely diagnosis is:

a. CCSA
b. chronic cutaneous lupus erythematosus
c. folliculitis decalvans
d. lichen planopilaris
e. trichotillomania

Review the PDF of the fact sheet on common hair disorders with board-relevant, easy-to-review material. This fact sheet reviews information about the most common hair disorders, including clinical and histopathological features, trichoscopy, and management of these diseases.

Practice Questions

1. A 40-year-old woman presents to the clinic with a burning sensation and tenderness on the scalp. At physical examination you notice erythematous papules and pustules on the vertex scalp. The most likely diagnosis is:

a. alopecia areata
b. CCSA
c. folliculitis decalvans
d. lichen planopilaris
e. traction alopecia

2. A 60-year-old woman presents with receding hair loss on the frontal and bitemporal scalp. She has noticed hair loss on her eyebrows. She has a history of oral ulcers. On physical examination there is mild erythema and perifollicular scales on the frontal hairline. A hair pull test is positive in this area. The most likely diagnosis is:

a. androgenetic alopecia
b. chronic cutaneous lupus erythematosus
c. frontal fibrosing alopecia
d. telogen effluvium
e. trichotillomania

3. A 5-year-old girl with a history of seasonal allergies and eczema presents with recurrent patchy hair loss on the scalp of 6 months’ duration. Her mother has noticed rapidly progressive hair loss affecting the whole scalp. On trichoscopy, you find yellow dots, broken hairs, and tapering hairs. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. telogen effluvium
d. traction alopecia
e. trichotillomania

4. A 30-year-old white woman with history of obsessive-compulsive disorder presents to the clinic with hair loss for the last 3 years. She says she has noticed worsening of the hair loss when she is under stress. She also bites her nails. On physical examination you identify an irregular patch of alopecia with broken hairs on the occipital scalp. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. lichen planopilaris
d. traction alopecia
e. trichotillomania

5. A 45-year-old black woman who has a family history of hair loss in her mother presents with tenderness and burning sensation on the vertex scalp. She reports the hair loss was worse after she got a hair relaxer 6 months prior. She uses braids on her scalp and she has not had a relaxer since then. The most likely diagnosis is:

a. CCSA
b. chronic cutaneous lupus erythematosus
c. folliculitis decalvans
d. lichen planopilaris
e. trichotillomania

Answers to practice questions provided on next page

Practice Question Answers

1. A 40-year-old woman presents to the clinic with a burning sensation and tenderness on the scalp. At physical examination you notice erythematous papules and pustules on the vertex scalp. The most likely diagnosis is:

a. alopecia areata
b. CCSA
c. folliculitis decalvans
d. lichen planopilaris
e. traction alopecia

2. A 60-year-old woman presents with receding hair loss on the frontal and bitemporal scalp. She has noticed hair loss on her eyebrows. She has a history of oral ulcers. On physical examination there is mild erythema and perifollicular scales on the frontal hairline. A hair pull test is positive in this area. The most likely diagnosis is:

a. androgenetic alopecia
b. chronic cutaneous lupus erythematosus
c. frontal fibrosing alopecia
d. telogen effluvium
e. trichotillomania

3. A 5-year-old girl with a history of seasonal allergies and eczema presents with recurrent patchy hair loss on the scalp of 6 months’ duration. Her mother has noticed rapidly progressive hair loss affecting the whole scalp. On trichoscopy, you find yellow dots, broken hairs, and tapering hairs. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. telogen effluvium
d. traction alopecia
e. trichotillomania

4. A 30-year-old white woman with history of obsessive-compulsive disorder presents to the clinic with hair loss for the last 3 years. She says she has noticed worsening of the hair loss when she is under stress. She also bites her nails. On physical examination you identify an irregular patch of alopecia with broken hairs on the occipital scalp. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. lichen planopilaris
d. traction alopecia
e. trichotillomania

5. A 45-year-old black woman who has a family history of hair loss in her mother presents with tenderness and burning sensation on the vertex scalp. She reports the hair loss was worse after she got a hair relaxer 6 months prior. She uses braids on her scalp and she has not had a relaxer since then. The most likely diagnosis is:

a. CCSA
b. chronic cutaneous lupus erythematosus
c. folliculitis decalvans
d. lichen planopilaris
e. trichotillomania

Review the PDF of the fact sheet on common hair disorders with board-relevant, easy-to-review material. This fact sheet reviews information about the most common hair disorders, including clinical and histopathological features, trichoscopy, and management of these diseases.

Practice Questions

1. A 40-year-old woman presents to the clinic with a burning sensation and tenderness on the scalp. At physical examination you notice erythematous papules and pustules on the vertex scalp. The most likely diagnosis is:

a. alopecia areata
b. CCSA
c. folliculitis decalvans
d. lichen planopilaris
e. traction alopecia

2. A 60-year-old woman presents with receding hair loss on the frontal and bitemporal scalp. She has noticed hair loss on her eyebrows. She has a history of oral ulcers. On physical examination there is mild erythema and perifollicular scales on the frontal hairline. A hair pull test is positive in this area. The most likely diagnosis is:

a. androgenetic alopecia
b. chronic cutaneous lupus erythematosus
c. frontal fibrosing alopecia
d. telogen effluvium
e. trichotillomania

3. A 5-year-old girl with a history of seasonal allergies and eczema presents with recurrent patchy hair loss on the scalp of 6 months’ duration. Her mother has noticed rapidly progressive hair loss affecting the whole scalp. On trichoscopy, you find yellow dots, broken hairs, and tapering hairs. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. telogen effluvium
d. traction alopecia
e. trichotillomania

4. A 30-year-old white woman with history of obsessive-compulsive disorder presents to the clinic with hair loss for the last 3 years. She says she has noticed worsening of the hair loss when she is under stress. She also bites her nails. On physical examination you identify an irregular patch of alopecia with broken hairs on the occipital scalp. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. lichen planopilaris
d. traction alopecia
e. trichotillomania

5. A 45-year-old black woman who has a family history of hair loss in her mother presents with tenderness and burning sensation on the vertex scalp. She reports the hair loss was worse after she got a hair relaxer 6 months prior. She uses braids on her scalp and she has not had a relaxer since then. The most likely diagnosis is:

a. CCSA
b. chronic cutaneous lupus erythematosus
c. folliculitis decalvans
d. lichen planopilaris
e. trichotillomania

Answers to practice questions provided on next page

Practice Question Answers

1. A 40-year-old woman presents to the clinic with a burning sensation and tenderness on the scalp. At physical examination you notice erythematous papules and pustules on the vertex scalp. The most likely diagnosis is:

a. alopecia areata
b. CCSA
c. folliculitis decalvans
d. lichen planopilaris
e. traction alopecia

2. A 60-year-old woman presents with receding hair loss on the frontal and bitemporal scalp. She has noticed hair loss on her eyebrows. She has a history of oral ulcers. On physical examination there is mild erythema and perifollicular scales on the frontal hairline. A hair pull test is positive in this area. The most likely diagnosis is:

a. androgenetic alopecia
b. chronic cutaneous lupus erythematosus
c. frontal fibrosing alopecia
d. telogen effluvium
e. trichotillomania

3. A 5-year-old girl with a history of seasonal allergies and eczema presents with recurrent patchy hair loss on the scalp of 6 months’ duration. Her mother has noticed rapidly progressive hair loss affecting the whole scalp. On trichoscopy, you find yellow dots, broken hairs, and tapering hairs. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. telogen effluvium
d. traction alopecia
e. trichotillomania

4. A 30-year-old white woman with history of obsessive-compulsive disorder presents to the clinic with hair loss for the last 3 years. She says she has noticed worsening of the hair loss when she is under stress. She also bites her nails. On physical examination you identify an irregular patch of alopecia with broken hairs on the occipital scalp. The most likely diagnosis is:

a. alopecia areata
b. androgenetic alopecia
c. lichen planopilaris
d. traction alopecia
e. trichotillomania

5. A 45-year-old black woman who has a family history of hair loss in her mother presents with tenderness and burning sensation on the vertex scalp. She reports the hair loss was worse after she got a hair relaxer 6 months prior. She uses braids on her scalp and she has not had a relaxer since then. The most likely diagnosis is:

a. CCSA
b. chronic cutaneous lupus erythematosus
c. folliculitis decalvans
d. lichen planopilaris
e. trichotillomania

Onychomycosis is a fungal infection of the nail unit by dermatophytes, yeasts, and nondermatophyte molds. It is characterized by a white or yellow discoloration of the nail plate; hyperkeratosis of the nail bed; distal detachment of the nail plate from its bed (onycholysis); and nail plate dystrophy, including thickening, crumbling, and ridging. Onychomycosis is an important problem, representing 30% of all superficial fungal infections and an estimated 50% of all nail diseases.¹ Reported prevalence rates of onychomycosis in the United States and worldwide are varied, but the mean prevalence based on population-based studies in Europe and North America is estimated to be 4.3%.² It is more common in older individuals, with an incidence rate of 20% in those older than 60 years and 50% in those older than 70 years.³ Onychomycosis is more common in patients with diabetes and 1.9 to 2.8 times higher than the general population.⁴ Dermatophytes are responsible for the majority of cases of onychomycosis, particularly Trichophyton rubrum and Trichophyton mentagrophytes.⁵

Onychomycosis is divided into different subtypes based on clinical presentation, which in turn are characterized by varying infecting organisms and prognoses. The subtypes of onychomycosis are distal and lateral subungual (DLSO), proximal subungual, superficial, endonyx, mixed pattern, total dystrophic, and secondary. Distal and lateral subungual onychomycosis are by far the most common presentation and begins when the infecting organism invades the hyponychium and distal or lateral nail bed. Trichophyton rubrum is the most common organism and T mentagrophytes is second, but Candida parapsilosis and Candida albicans also are possibilities. Proximal subungual onychomycosis is far less frequent than DLSO and is usually caused by T rubrum. The fungus invades the proximal nail folds and penetrates the newly growing nail plate.⁶ This pattern is more common in immunosuppressed patients and should prompt testing for human immunodeficiency virus.⁷ Total dystrophic onychomycosis is the end stage of fungal nail plate invasion, may follow DLSO or proximal subungual onychomycosis, and is difficult to treat.⁶

Onychomycosis causes pain, paresthesia, and difficulty with ambulation.⁸ In patients with peripheral neuropathy and vascular problems, including diabetes, onychomycosis can increase the risk for foot ulcers, with amputation in severe cases.⁹ Patients also may present with aesthetic concerns that may impact their quality of life.¹⁰

Given the effect on quality of life along with medical risks associated with onychomycosis, a safe and successful treatment modality with a low risk of recurrence is desirable. Unfortunately, treatment of nail fungus is quite challenging for a number of reasons. First, the thickness of the nail and/or the fungal mass may be a barrier to the delivery of topical and systemic drugs at the source of the infection. In addition, the nail plate does not have intrinsic immunity. Also, recurrence after treatment is common due to residual hyphae or spores that were not previously eliminated.¹¹ Finally, many topical medications require long treatment courses, which may limit patient compliance, especially in patients who want to use nail polish for cosmesis or camouflage.

Currently Approved Therapies for Onychomycosis

Several definitions are needed to better interpret the results of onychomycosis clinical trials. Complete cure is defined as a negative potassium hydroxide preparation and negative fungal culture with a completely normal appearance of the nail. Mycological cure is defined as potassium hydroxide microscopy and fungal culture negative. Clinical cure is stated as 0% nail plate involvement but at times is reported as less than 5% and less than 10% involvement.

Terbinafine and itraconazole are the only US Food and Drug Administration (FDA)–approved systemic therapies, and ciclopirox, efinaconazole, and tavaborole are the only FDA-approved topicals. Advantages of systemic agents generally are higher cure rates and shorter treatment courses, thus better compliance. Disadvantages include greater incidence of systemic side effects and drug-drug interactions as well as the need for laboratory monitoring. Pros of topical therapies are low potential for adverse effects, no drug-drug interactions, and no monitoring of blood work. Cons include lower efficacy, long treatment courses, and poor patient compliance.

Terbinafine, an allylamine, taken orally once daily (250 mg) for 12 weeks for toenails and 6 weeks for fingernails currently is the preferred systemic treatment of onychomycosis, with complete cure rates of 38% and 59% and mycological cure rates of 70% and 79% for toenails and fingernails, respectively.¹² Itraconazole, an azole, is dosed orally at 200 mg daily for 3 months for toenails, with a complete cure rate of 14% and mycological cure rate of 54%.¹³ For fingernail onychomycosis only, itraconazole is dosed at 200 mg twice daily for 1 week, followed by a treatment-free period of 3 weeks, and then another 1-week course at thesame dose. The complete cure rate is 47% and the mycological cure is 61% for this pulse regimen.¹³

Ciclopirox is a hydroxypyridone and the 8% nail lacquer formulation was approved in 1999, making it the first topical medication to gain FDA approval for the treatment of toenail onychomycosis. Based on 2 clinical trials, complete cure rates for toenails are 5.5% and 8.5% and mycological cure rates are 29% and 36% at 48 weeks with removal of residual lacquer and debridement.¹⁴Efinaconazole is an azole and the 10% solution was FDA approved for the treatment of toenail onychomycosis in 2014.¹⁵ In 2 clinical trials, complete cure rates were 17.8% and 15.2% and mycological cure rates were 55.2% and 53.4% with once daily toenail application for 48 weeks.¹⁶ Tavaborole is a benzoxaborole and the 5% solution also was approved for the treatment of toenail onychomycosis in 2014.¹⁷ Two clinical trials reported complete cure rates of 6.5% and 9.1% and mycological cure rates of 31.1% and 35.9% with once daily toenail application for 48 weeks.¹⁸

Given the poor efficacy, systemic side effects, potential for drug-drug interactions, long-term treatment courses, and cost associated with current systemic and/or topical treatments, there has been a renewed interest in natural remedies and over-the-counter (OTC) therapies for onychomycosis. This review summarizes the in vitro and in vivo data, mechanisms of action, and clinical efficacy of various natural and OTC agents for the treatment of onychomycosis. Specifically, we summarize the data on tea tree oil (TTO), a popular topical cough suppressant (TCS), natural coniferous resin (NCR) lacquer, Ageratina pichinchensis (AP) extract, and ozonized sunflower oil.

Tea Tree Oil

Background

Tea tree oil is a volatile oil whose medicinal use dates back to the early 20th century when the Bundjabung aborigines of North and New South Wales extracted TTO from the dried leaves of the Melaleuca alternifolia plant and used it to treat superficial wounds.¹⁹ Tea tree oil has been shown to be an effective treatment of tinea pedis,²⁰ and it is widely used in Australia as well as in Europe and North America.²¹ Tea tree oil also has been investigated as an antifungal agent for the treatment of onychomycosis, both in vitro^22-28 and in clinical trials.^29,30

In Vitro Data

Because TTO is composed of more than 100 active components,²³ the antifungal activity of these individual components was investigated against 14 fungal isolates, including C albicans, T mentagrophytes, and Aspergillus species. The minimum inhibitory concentration (MIC) for α-pinene was less than 0.004% for T mentagrophytes and the components with the greatest MIC and minimum fungicidal concentration for the fungi tested were terpinen-4-ol and α-terpineol, respectively.²² The antifungal activity of TTO also was tested using disk diffusion assay experiments with 58 clinical isolates of fungi including C albicans, T rubrum, T mentagrophytes, and Aspergillus niger.²⁴ Tea tree oil was most effective at inhibiting T rubrum followed by T mentagrophytes,²⁴ which are the 2 most common etiologies of onychomycosis.⁵ In another report, the authors determined the MIC of TTO utilizing 4 different experiments with T rubrum as the infecting organism. Because TTO inhibited the growth of T rubrum at all concentrations greater than 0.1%, they found that the MIC was 0.1%.²⁵ Given the lack of adequate nail penetration of most topical therapies, TTO in nanocapsules (TTO-NC), TTO nanoemulsions, and normal emulsions were tested in vitro for their ability to inhibit the growth of T rubrum inoculated into nail shavings. Colony growth decreased significantly within the first week of treatment, with TTO-NC showing maximum efficacy (P<.001). This study showed that TTO, particularly TTO-NC, was effective in inhibiting the growth of T rubrum in vitro and that using nanocapsule technology may increase nail penetration and bioavailability.³¹

Much of what we know about TTO’s antifungal mechanism of action comes from experiments involving C albicans. To date, it has not been studied in T rubrum or T mentagrophytes, the 2 most common etiologies of onychomycosis.⁵ In C albicans, TTO causes altered permeability of plasma membranes,³² dose-dependent alteration of respiration,³³ decreased glucose-induced acidification of media surrounding fungi,³² and reversible inhibition of germ tube formation.^19,34

Clinical Trials

A randomized, double-blind, multicenter trial was performed on 117 patients with culture-proven DLSO who were randomized to receive TTO 100% or clotrimazole solution 1% applied twice daily to affected toenails for 6 months.²⁹ Primary outcome measures were mycologic cure, clinical assessment, and patient subjective assessment (Table 1). There were no statistical differences between the 2 treatment groups. Erythema and irritation were the most common adverse reactions occurring in 7.8% (5/64) of the TTO group.²⁹

Another study was a double-blind, placebo-controlled trial involving 60 patients with clinical and mycologic evidence of DLSO who were randomized to treatment with a cream containing butenafine hydrochloride 2% and TTO 5% (n=40) or a control cream containing only TTO (n=20), with active treatment for 8 weeks and final follow-up at 36 weeks.³⁰ Patients were instructed to apply the cream 3 times daily under occlusion for 8 weeks and the nail was debrided between weeks 4 and 6 if feasible. If the nail could not be debrided after 8 weeks, it was considered resistant to treatment. At the end of the study, the complete cure rate was 80% in the active group compared to 0% in the placebo group (P<.0001), and the mean time to complete healing with progressive nail growth was 29 weeks. There were no adverse effects in the placebo group, but 4 patients in the active group had mild skin inflammation.³⁰

Topical Cough Suppressant

Background

Topical cough suppressants, which are made up of several natural ingredients, are OTC ointments for adults and children 2 years and older that are indicated as cough suppressants when applied to the chest and throat and as relief of mild muscle and joint pains.³⁵ The active ingredients are camphor 4.8%, eucalyptus oil 1.2%, and menthol 2.6%, while the inactive ingredients are cedarleaf oil, nutmeg oil, petrolatum, thymol, and turpentine oil.³⁵ Some of the active and inactive ingredients in TCSs have shown efficacy against dermatophytes in vitro,^36-38 and although they are not specifically indicated for onychomycosis, they have been popularized as home remedies for fungal nail infections.^36,39 A TCS has been evaluated for its efficacy for the treatment of onychomycosis in one clinical trial.⁴⁰

In Vitro Data

An in vitro study was performed to evaluate the antifungal activity of the individual and combined components of TCS on 16 different dermatophytes, nondermatophytes, and molds. The zones of inhibition against these organisms were greatest for camphor, menthol, thymol, and eucalyptus oil. Interestingly, there were large zones of inhibition and a synergistic effect when a mixture of components was used against T rubrum and T mentagrophytes.³⁶ The in vitro activity of thymol, a component of TCS, was tested against Candida species.³⁷ The essential oil subtypes Thymus vulgaris and Thymus zygis (subspecies zygis) showed similar antifungal activity, which was superior to Thymus mastichina, and all 3 compounds had similar MIC and minimal lethal concentration values. The authors showed that the antifungal mechanism was due to cell membrane damage and inhibition of germ tube formation.³⁷ It should be noted that Candida species are less common causes of onychomycosis, and it is not known whether this data is applicable to T rubrum. In another study, the authors investigated the antifungal activity of Thymus pulegioides and found that MIC ranged from 0.16 to 0.32 μL/mL for dermatophytes and Aspergillus strains and 0.32 to 0.64 μL/mL for Candida species. When an essential oil concentration of 0.08 μL/mL was used against T rubrum, ergosterol content decreased by 70 %, indicating that T pulegioides inhibits ergosterol biosynthesis in T rubrum.³⁸

Clinical Observations and Clinical Trial

There is one report documenting the clinical observations on a group of patients with a clinical diagnosis of onychomycosis who were instructed to apply TCS to affected nail(s) once daily.³⁶ Eighty-five charts were reviewed (mean age, 77 years), and although follow-up was not complete or standardized, the following data were reported: 32 (38%) cleared their fungal infection, 21 (25%) had no record of change but also no record of compliance, 19 (22%) had only 1 documented follow-up visit, 9 (11%) reported they did not use the treatment, and 4 (5%) did not return for a follow-up visit. Of the 32 patients whose nails were cured, 3 (9%) had clearance within 5 months, 8 (25%) within 7 months, 11 (34%) within 9 months, 4 (13%) within 11 months, and 6 (19%) within 16 months.³⁶

A small pilot study was performed to evaluate the efficacy of daily application of TCS in the treatment of onychomycosis in patients 18 years and older with at least 1 great toenail affected.⁴⁰ The primary end points were mycologic cure at 48 weeks and clinical cure at the end of the study graded as complete, partial, or no change. The secondary end point was patient satisfaction with the appearance of the affected nail at 48 weeks. Eighteen participants completed the study; 55% (10/18) were male, with an average age of 51 years (age range, 30–85 years). The mean initial amount of affected nail was 62% (range, 16%–100%), and cultures included dermatophytes, nondermatophytes, and molds. With TCS treatment, 27.8% (5/18) showed mycologic cure of which 4 (22.2%) had a complete clinical cure. Ten participants (55.6%) had partial clinical cure and 3 (16.7%) had no clinical improvement. Interestingly, the 4 participants who had complete clinical cure had baseline cultures positive for either T mentagrophytes or C parapsilosis. Most patients were content with the treatment, as 9 participants stated that they were very satisfied and 9 stated that they were satisfied. The average ratio of affected to total nail area declined from 63% at screening to 41% at the end of the study (P<.001). No adverse effects were reported with study drug.⁴⁰

NCR Lacquer

Background

Resins are natural products derived from coniferous trees and are believed to protect trees against insects and microbial pathogens.⁴¹ Natural coniferous resin derived from the Norway spruce tree (Picea abies) mixed with boiled animal fat or butter has been used topically for centuries in Finland and Sweden to treat infections and wounds.^42-44 The activity of NCR has been studied against a wide range of microbes, demonstrating broad-spectrum antimicrobial activity against both gram-positive bacteria and fungi.^45-48 There are 2 published clinical trials evaluating NCR in the treatment of onychomycosis.^49,50

In Vitro Data

Natural coniferous resin has shown antifungal activity against T mentagrophytes, Trichophyton tonsurans, and T rubrum in vitro, which was demonstrated using medicated disks of resin on petri dishes inoculated with these organisms.⁴⁶ In another study, the authors evaluated the antifungal activity of NCR against human pathogenic fungi and yeasts using agar plate diffusion tests and showed that the resin had antifungal activity against Trichophyton species but not against Fusarium and most Candida species. Electron microscopy of T mentagrophytes exposed to NCR showed that all cells were dead inside the inhibition zone, with striking changes seen in the hyphal cell walls, while fungal cells outside the inhibition zone were morphologically normal.⁴⁷ In another report, utilizing the European Pharmacopoeia challenge test, NCR was highly effective against gram-positive and gram-negative bacteria as well as C albicans.⁴²

Clinical Trials

In one preliminary observational and prospective clinical trial, 15 participants with clinical and mycologic evidence of onychomycosis were instructed to apply NCR lacquer once daily for 9 months with a 4-week washout period, with the primary outcome measures being clinical and mycologic cure.⁴⁹ Thirteen (87%) enrolled participants were male and the average age was 65 years (age range, 37–80 years). The DLSO subtype was present in 9 (60%) participants. The mycologic cure rate at the end of the study was 65% (95% CI, 42%-87%), and none achieved clinical cure, but 6 participants showed some improvement in the appearance of the nail.⁴⁹

The second trial was a prospective, controlled, investigator-blinded study of 73 patients with clinical and mycologic evidence of toenail onychomycosis who were randomized to receive NCR 30%, amorolfine lacquer 5%, or 250 mg oral terbinafine.⁵⁰ The primary end point was mycologic cure at 10 months, and secondary end points were clinical efficacy, cost-effectiveness, and patient compliance. Clinical efficacy was based on the proximal linear growth of healthy nail and was classified as unchanged, partial, or complete. Partial responses were described as substantial decreases in onycholysis, subungual hyperkeratosis, and streaks. A complete response was defined as a fully normal appearance of the toenail. Most patients were male in the NCR (91% [21/23]), amorolfine (80% [20/25]), and terbinafine (68% [17/25]) groups; the average ages were 64, 63, and 64 years, respectively. Trichophyton rubrum was cultured most often in all 3 groups: NCR, 87% (20/23); amorolfine, 96% (24/25); and terbinafine, 84% (21/25). The remaining cases were from T mentagrophytes. A summary of the results is shown in Table 2. Patient compliance was 100% in all except 1 patient in the amorolfine treatment group with moderate compliance. There were no adverse events, except for 2 in the terbinafine group: diarrhea and rash.⁵⁰

AP Extract

Background

Ageratina pichinchensis, a member of the Asteraceae family, has been used historically in Mexico for fungal infections of the skin.^51,52 Fresh or dried leaves were extracted with alcohol and the product was administered topically onto damaged skin without considerable skin irritation.⁵³ Multiple studies have demonstrated that AP extract has in vitro antifungal activity along with other members of the Asteraceae family.^54-56 There also is evidence from clinical trials that AP extract is effective against superficial dermatophyte infections such as tinea pedis.⁵⁷ Given the positive antifungal in vitro data, the potential use of this agent was investigated for onychomycosis treatment.^53,58

In Vitro Data

The antifungal properties of the Asteraceae family have been tested in several in vitro experiments. Eupatorium aschenbornianum, described as synonymous with A pichinchensis,⁵⁹ was found to be most active against the dermatophytes T rubrum and T mentagrophytes with MICs of 0.3 and 0.03 mg/mL, respectively.⁵⁴ It is thought that the primary antimycotic activity is due to encecalin, an acetylchromene compound that was identified in other plants from the Asteraceae family and has activity against dermatophytes.⁵⁵ In another study, Ageratum houstanianum Mill, a comparable member of the Asteraceae family, had fungitoxic activity against T rubrum and C albicans isolated from nail infections.⁵⁶

Clinical Trials

A double-blind controlled trial was performed on 110 patients with clinical and mycologic evidence of mild to moderate toenail onychomycosis randomized to treatment with AP lacquer or ciclopirox lacquer 8% (control).⁵⁸ Primary end points were clinical effectiveness (completely normal nails) and mycologic cure. Patients were instructed to apply the lacquer once every third day during the first month, twice a week for the second month, and once a week for 16 weeks, with removal of the lacquer weekly. Demographics were similar between the AP lacquer and control groups, with mean ages of 44.6 and 46.5 years, respectively; women made up 74.5% and 67.2%, respectively, of each treatment group, with most patients having a 2- to 5-year history of disease (41.8% and 40.1%, respectively).⁵⁸ A summary of the data is shown in Table 3. No severe side effects were documented, but minimal nail fold skin pain was reported in 3 patients in the control group in the first week, resolving later in the trial.⁵⁸

A follow-up study was performed to determine the optimal concentration of AP lacquer for the treatment of onychomycosis.⁵³ One hundred twenty-two patients aged 19 to 65 years with clinical and mycologic evidence of mild to moderate DLSO were randomized to receive 12.6% or 16.8% AP lacquer applied once daily to the affected nails for 6 months. The nails were graded as healthy, mild, or moderately affected before and after treatment. There were no significant differences in demographics between the 2 treatment groups, and 77% of patients were women with a median age of 47 years. There were no significant side effects from either concentration of AP lacquer.⁵³

Ozonized Sunflower Oil

Background

Ozonized sunflower oil is derived by reacting ozone (O₃) with sunflower plant (Helianthus annuus) oil to form a petroleum jelly–like material.⁶⁰ It was originally shown to have antibacterial properties in vitro,⁶¹ and further studies have confirmed these findings and demonstrated anti-inflammatory, wound healing, and antifungal properties.^62-64 A formulation of ozonized sunflower oil used in Cuba is clinically indicated for the treatment of tinea pedis and impetigo.⁶⁵ The clinical efficacy of this product has been evaluated in a clinical trial for the treatment of onychomycosis.⁶⁵

In Vitro Data

A compound made up of 30% ozonized sunflower oil with 0.5% of α-lipoic acid was found to have antifungal activity against C albicans using the disk diffusion method, in addition to other bacterial organisms. The MIC values ranged from 2.0 to 3.5 mg/mL.⁶² Another study was designed to evaluate the in vitro antifungal activity of this formulation on samples cultured from patients with onychomycosis using the disk diffusion method. They found inhibition of growth of C albicans, C parapsilosis, and Candida tropicalis, which was inferior to amphotericin B, ketoconazole, fluconazole, and itraconazole.⁶⁴

Clinical Trial

A single-blind, controlled, phase 3 study was performed on 400 patients with clinical and mycologic evidence of onychomycosis. Patients were randomized to treatment with an ozonized sunflower oil solution or ketoconazole cream 2% applied to affected nails twice daily for 3 months, with filing and massage of the affected nails upon application of treatment.⁶⁵ Cured was defined as mycologic cure in addition to a healthy appearing nail, improved as an increase in healthy appearing nail in addition to a decrease in symptoms (ie, paresthesia, pain, itching) but positive mycological testing, same as no clinical change in appearance with positive mycological findings, and worse as increasing diseased nail involvement in the presence of positive mycological findings. Demographics were similar between groups with a mean age of 35 years. Men accounted for 80% of the study population, and 65% of the study population was white. The mean duration of disease was 30 months. They also reported on a 1-year follow-up, with 2.8% of patients in the ozonized sunflower oil solution group and 37.0% of patients in the ketoconazole group describing relapses. Trichophyton rubrum and C albicans were cultured from these patients.⁶⁵

Comment

Due to the poor efficacy, long-term treatment courses, inability to use nail polish, and high cost associated with many FDA-approved topical treatments, along with the systemic side effects, potential for drug-drug interactions, and cost associated with many oral therapies approved for onychomycosis, there has been a renewed interest in natural remedies and OTC treatments. Overall, TTO, TCS, NCR, AP extract, and ozonized sunflower oil have shown efficacy in vitro against some dermatophytes, nondermatophytes, and molds responsible for onychomycosis. One or more clinical trials were performed with each of these agents for the treatment of onychomycosis. They were mostly small pilot studies, and due to differences in trial design, the results cannot be compared with each other or with currently FDA-approved treatments. We can conclude that because adverse events were rare with all of these therapies—most commonly skin irritation or mild skin pain—they exhibit good safety.

For TTO, there was no statistical difference between the clotrimazole and TTO treatment groups in mycologic cure, clinical assessment, or patient subjective assessment of the nails.²⁹ Although there was an 80% complete cure in the butenafine and TTO group, it was 0% in the TTO group at week 36.³⁰ Trial design, longer treatment periods, incorporation into nanocapsules, or combination treatment with other antifungal agents may influence our future use of TTO for onychomycosis, but based on the present data we cannot recommend this treatment in clinical practice.

With TCS, 27.8% of participants had a mycologic cure and 22.2% had complete clinical cure.⁴⁰ Although it is difficult to draw firm conclusions from this small pilot study, there may be some benefit to treating toenail onychomycosis due to T mentagrophytes or C parapsilosis with TCS but no benefit in treating onychomycosis due to T rubrum, the more common cause of onychomycosis. Limitations of this study were lack of a placebo group, small sample size, wide variety of represented pathogens that may not be representative of the true population, and lack of stratification by baseline severity or involvement of nail. A larger randomized controlled clinical trial would be necessary to confirm the results of this small study and make formal recommendations.

In one clinical trial with NCR, mycologic cure was 65% at the end of the study.⁴⁹ No participants achieved clinical cure, but 6 participants showed some improvement in the appearance of the nail. Because this study was small (N=15), it is difficult to draw firm conclusions.⁴⁹ In another study with NCR, mycologic cure rates with NCR, amorolfine, and terbinafine were 13%, 8%, and 56%, respectively. Based on these results, NCR has similar antifungal efficacy to amorolfine but was inferior to oral terbinafine.⁵⁰ A larger randomized controlled clinical trial with more homogenous and less severely affected patients and longer treatment periods would be necessary to confirm the results of these small studies and make formal recommendations.

Because there were no significant differences in clinical effectiveness of mycologic cure rates between AP lacquer 10% and ciclopirox lacquer 8% in one clinical trial,⁵⁸ AP does not seem to be more effective than at least one of the current FDA-approved topical treatments; however, because AP lacquer 16.8% was shown to be more effective than AP lacquer 12.6% in one onychomycosis clinical trial, using higher concentrations of AP may yield better results in future trials.⁵³

One trial comparing ozonized sunflower oil to ketoconazole cream 2% showed 90.5% and 13.5% cure rates, respectively.⁶⁵ Although there is good in vitro antifungal activity and a clinical trial showing efficacy using ozonized sunflower oil for the treatment of onychomycosis, confirmatory studies are necessary before we can recommend this OTC treatment to our patients. Specifically, we will get the most data from large randomized controlled trials with strict inclusion/exclusion and efficacy criteria.

Conclusion

Over-the-counter and natural remedies may be an emerging area of research in the treatment of onychomycosis. This review summarizes the laboratory data and clinical trials on several of these agents and, when available, compares their clinical and mycologic efficacy with FDA-approved therapies. Shortcomings of some of these studies include a small study population, lack of adequate controls, nonstandardized mycologic testing, and abbreviated posttreatment evaluation times. It may be concluded that these products have varying degrees of efficacy and appear to be safe in the studies cited; however, at present, we cannot recommend any of them to our patients until there are larger randomized clinical trials with appropriate controls demonstrating their efficacy.

Onychomycosis is a fungal infection of the nail unit by dermatophytes, yeasts, and nondermatophyte molds. It is characterized by a white or yellow discoloration of the nail plate; hyperkeratosis of the nail bed; distal detachment of the nail plate from its bed (onycholysis); and nail plate dystrophy, including thickening, crumbling, and ridging. Onychomycosis is an important problem, representing 30% of all superficial fungal infections and an estimated 50% of all nail diseases.¹ Reported prevalence rates of onychomycosis in the United States and worldwide are varied, but the mean prevalence based on population-based studies in Europe and North America is estimated to be 4.3%.² It is more common in older individuals, with an incidence rate of 20% in those older than 60 years and 50% in those older than 70 years.³ Onychomycosis is more common in patients with diabetes and 1.9 to 2.8 times higher than the general population.⁴ Dermatophytes are responsible for the majority of cases of onychomycosis, particularly Trichophyton rubrum and Trichophyton mentagrophytes.⁵

Onychomycosis is divided into different subtypes based on clinical presentation, which in turn are characterized by varying infecting organisms and prognoses. The subtypes of onychomycosis are distal and lateral subungual (DLSO), proximal subungual, superficial, endonyx, mixed pattern, total dystrophic, and secondary. Distal and lateral subungual onychomycosis are by far the most common presentation and begins when the infecting organism invades the hyponychium and distal or lateral nail bed. Trichophyton rubrum is the most common organism and T mentagrophytes is second, but Candida parapsilosis and Candida albicans also are possibilities. Proximal subungual onychomycosis is far less frequent than DLSO and is usually caused by T rubrum. The fungus invades the proximal nail folds and penetrates the newly growing nail plate.⁶ This pattern is more common in immunosuppressed patients and should prompt testing for human immunodeficiency virus.⁷ Total dystrophic onychomycosis is the end stage of fungal nail plate invasion, may follow DLSO or proximal subungual onychomycosis, and is difficult to treat.⁶

Onychomycosis causes pain, paresthesia, and difficulty with ambulation.⁸ In patients with peripheral neuropathy and vascular problems, including diabetes, onychomycosis can increase the risk for foot ulcers, with amputation in severe cases.⁹ Patients also may present with aesthetic concerns that may impact their quality of life.¹⁰

Given the effect on quality of life along with medical risks associated with onychomycosis, a safe and successful treatment modality with a low risk of recurrence is desirable. Unfortunately, treatment of nail fungus is quite challenging for a number of reasons. First, the thickness of the nail and/or the fungal mass may be a barrier to the delivery of topical and systemic drugs at the source of the infection. In addition, the nail plate does not have intrinsic immunity. Also, recurrence after treatment is common due to residual hyphae or spores that were not previously eliminated.¹¹ Finally, many topical medications require long treatment courses, which may limit patient compliance, especially in patients who want to use nail polish for cosmesis or camouflage.

Currently Approved Therapies for Onychomycosis

Several definitions are needed to better interpret the results of onychomycosis clinical trials. Complete cure is defined as a negative potassium hydroxide preparation and negative fungal culture with a completely normal appearance of the nail. Mycological cure is defined as potassium hydroxide microscopy and fungal culture negative. Clinical cure is stated as 0% nail plate involvement but at times is reported as less than 5% and less than 10% involvement.

Terbinafine and itraconazole are the only US Food and Drug Administration (FDA)–approved systemic therapies, and ciclopirox, efinaconazole, and tavaborole are the only FDA-approved topicals. Advantages of systemic agents generally are higher cure rates and shorter treatment courses, thus better compliance. Disadvantages include greater incidence of systemic side effects and drug-drug interactions as well as the need for laboratory monitoring. Pros of topical therapies are low potential for adverse effects, no drug-drug interactions, and no monitoring of blood work. Cons include lower efficacy, long treatment courses, and poor patient compliance.

Terbinafine, an allylamine, taken orally once daily (250 mg) for 12 weeks for toenails and 6 weeks for fingernails currently is the preferred systemic treatment of onychomycosis, with complete cure rates of 38% and 59% and mycological cure rates of 70% and 79% for toenails and fingernails, respectively.¹² Itraconazole, an azole, is dosed orally at 200 mg daily for 3 months for toenails, with a complete cure rate of 14% and mycological cure rate of 54%.¹³ For fingernail onychomycosis only, itraconazole is dosed at 200 mg twice daily for 1 week, followed by a treatment-free period of 3 weeks, and then another 1-week course at thesame dose. The complete cure rate is 47% and the mycological cure is 61% for this pulse regimen.¹³

Ciclopirox is a hydroxypyridone and the 8% nail lacquer formulation was approved in 1999, making it the first topical medication to gain FDA approval for the treatment of toenail onychomycosis. Based on 2 clinical trials, complete cure rates for toenails are 5.5% and 8.5% and mycological cure rates are 29% and 36% at 48 weeks with removal of residual lacquer and debridement.¹⁴Efinaconazole is an azole and the 10% solution was FDA approved for the treatment of toenail onychomycosis in 2014.¹⁵ In 2 clinical trials, complete cure rates were 17.8% and 15.2% and mycological cure rates were 55.2% and 53.4% with once daily toenail application for 48 weeks.¹⁶ Tavaborole is a benzoxaborole and the 5% solution also was approved for the treatment of toenail onychomycosis in 2014.¹⁷ Two clinical trials reported complete cure rates of 6.5% and 9.1% and mycological cure rates of 31.1% and 35.9% with once daily toenail application for 48 weeks.¹⁸

Given the poor efficacy, systemic side effects, potential for drug-drug interactions, long-term treatment courses, and cost associated with current systemic and/or topical treatments, there has been a renewed interest in natural remedies and over-the-counter (OTC) therapies for onychomycosis. This review summarizes the in vitro and in vivo data, mechanisms of action, and clinical efficacy of various natural and OTC agents for the treatment of onychomycosis. Specifically, we summarize the data on tea tree oil (TTO), a popular topical cough suppressant (TCS), natural coniferous resin (NCR) lacquer, Ageratina pichinchensis (AP) extract, and ozonized sunflower oil.

Tea Tree Oil

Background

Tea tree oil is a volatile oil whose medicinal use dates back to the early 20th century when the Bundjabung aborigines of North and New South Wales extracted TTO from the dried leaves of the Melaleuca alternifolia plant and used it to treat superficial wounds.¹⁹ Tea tree oil has been shown to be an effective treatment of tinea pedis,²⁰ and it is widely used in Australia as well as in Europe and North America.²¹ Tea tree oil also has been investigated as an antifungal agent for the treatment of onychomycosis, both in vitro^22-28 and in clinical trials.^29,30

In Vitro Data

Because TTO is composed of more than 100 active components,²³ the antifungal activity of these individual components was investigated against 14 fungal isolates, including C albicans, T mentagrophytes, and Aspergillus species. The minimum inhibitory concentration (MIC) for α-pinene was less than 0.004% for T mentagrophytes and the components with the greatest MIC and minimum fungicidal concentration for the fungi tested were terpinen-4-ol and α-terpineol, respectively.²² The antifungal activity of TTO also was tested using disk diffusion assay experiments with 58 clinical isolates of fungi including C albicans, T rubrum, T mentagrophytes, and Aspergillus niger.²⁴ Tea tree oil was most effective at inhibiting T rubrum followed by T mentagrophytes,²⁴ which are the 2 most common etiologies of onychomycosis.⁵ In another report, the authors determined the MIC of TTO utilizing 4 different experiments with T rubrum as the infecting organism. Because TTO inhibited the growth of T rubrum at all concentrations greater than 0.1%, they found that the MIC was 0.1%.²⁵ Given the lack of adequate nail penetration of most topical therapies, TTO in nanocapsules (TTO-NC), TTO nanoemulsions, and normal emulsions were tested in vitro for their ability to inhibit the growth of T rubrum inoculated into nail shavings. Colony growth decreased significantly within the first week of treatment, with TTO-NC showing maximum efficacy (P<.001). This study showed that TTO, particularly TTO-NC, was effective in inhibiting the growth of T rubrum in vitro and that using nanocapsule technology may increase nail penetration and bioavailability.³¹

Much of what we know about TTO’s antifungal mechanism of action comes from experiments involving C albicans. To date, it has not been studied in T rubrum or T mentagrophytes, the 2 most common etiologies of onychomycosis.⁵ In C albicans, TTO causes altered permeability of plasma membranes,³² dose-dependent alteration of respiration,³³ decreased glucose-induced acidification of media surrounding fungi,³² and reversible inhibition of germ tube formation.^19,34

Clinical Trials

A randomized, double-blind, multicenter trial was performed on 117 patients with culture-proven DLSO who were randomized to receive TTO 100% or clotrimazole solution 1% applied twice daily to affected toenails for 6 months.²⁹ Primary outcome measures were mycologic cure, clinical assessment, and patient subjective assessment (Table 1). There were no statistical differences between the 2 treatment groups. Erythema and irritation were the most common adverse reactions occurring in 7.8% (5/64) of the TTO group.²⁹

Another study was a double-blind, placebo-controlled trial involving 60 patients with clinical and mycologic evidence of DLSO who were randomized to treatment with a cream containing butenafine hydrochloride 2% and TTO 5% (n=40) or a control cream containing only TTO (n=20), with active treatment for 8 weeks and final follow-up at 36 weeks.³⁰ Patients were instructed to apply the cream 3 times daily under occlusion for 8 weeks and the nail was debrided between weeks 4 and 6 if feasible. If the nail could not be debrided after 8 weeks, it was considered resistant to treatment. At the end of the study, the complete cure rate was 80% in the active group compared to 0% in the placebo group (P<.0001), and the mean time to complete healing with progressive nail growth was 29 weeks. There were no adverse effects in the placebo group, but 4 patients in the active group had mild skin inflammation.³⁰

Topical Cough Suppressant

Background

Topical cough suppressants, which are made up of several natural ingredients, are OTC ointments for adults and children 2 years and older that are indicated as cough suppressants when applied to the chest and throat and as relief of mild muscle and joint pains.³⁵ The active ingredients are camphor 4.8%, eucalyptus oil 1.2%, and menthol 2.6%, while the inactive ingredients are cedarleaf oil, nutmeg oil, petrolatum, thymol, and turpentine oil.³⁵ Some of the active and inactive ingredients in TCSs have shown efficacy against dermatophytes in vitro,^36-38 and although they are not specifically indicated for onychomycosis, they have been popularized as home remedies for fungal nail infections.^36,39 A TCS has been evaluated for its efficacy for the treatment of onychomycosis in one clinical trial.⁴⁰

In Vitro Data

An in vitro study was performed to evaluate the antifungal activity of the individual and combined components of TCS on 16 different dermatophytes, nondermatophytes, and molds. The zones of inhibition against these organisms were greatest for camphor, menthol, thymol, and eucalyptus oil. Interestingly, there were large zones of inhibition and a synergistic effect when a mixture of components was used against T rubrum and T mentagrophytes.³⁶ The in vitro activity of thymol, a component of TCS, was tested against Candida species.³⁷ The essential oil subtypes Thymus vulgaris and Thymus zygis (subspecies zygis) showed similar antifungal activity, which was superior to Thymus mastichina, and all 3 compounds had similar MIC and minimal lethal concentration values. The authors showed that the antifungal mechanism was due to cell membrane damage and inhibition of germ tube formation.³⁷ It should be noted that Candida species are less common causes of onychomycosis, and it is not known whether this data is applicable to T rubrum. In another study, the authors investigated the antifungal activity of Thymus pulegioides and found that MIC ranged from 0.16 to 0.32 μL/mL for dermatophytes and Aspergillus strains and 0.32 to 0.64 μL/mL for Candida species. When an essential oil concentration of 0.08 μL/mL was used against T rubrum, ergosterol content decreased by 70 %, indicating that T pulegioides inhibits ergosterol biosynthesis in T rubrum.³⁸

Clinical Observations and Clinical Trial

There is one report documenting the clinical observations on a group of patients with a clinical diagnosis of onychomycosis who were instructed to apply TCS to affected nail(s) once daily.³⁶ Eighty-five charts were reviewed (mean age, 77 years), and although follow-up was not complete or standardized, the following data were reported: 32 (38%) cleared their fungal infection, 21 (25%) had no record of change but also no record of compliance, 19 (22%) had only 1 documented follow-up visit, 9 (11%) reported they did not use the treatment, and 4 (5%) did not return for a follow-up visit. Of the 32 patients whose nails were cured, 3 (9%) had clearance within 5 months, 8 (25%) within 7 months, 11 (34%) within 9 months, 4 (13%) within 11 months, and 6 (19%) within 16 months.³⁶

A small pilot study was performed to evaluate the efficacy of daily application of TCS in the treatment of onychomycosis in patients 18 years and older with at least 1 great toenail affected.⁴⁰ The primary end points were mycologic cure at 48 weeks and clinical cure at the end of the study graded as complete, partial, or no change. The secondary end point was patient satisfaction with the appearance of the affected nail at 48 weeks. Eighteen participants completed the study; 55% (10/18) were male, with an average age of 51 years (age range, 30–85 years). The mean initial amount of affected nail was 62% (range, 16%–100%), and cultures included dermatophytes, nondermatophytes, and molds. With TCS treatment, 27.8% (5/18) showed mycologic cure of which 4 (22.2%) had a complete clinical cure. Ten participants (55.6%) had partial clinical cure and 3 (16.7%) had no clinical improvement. Interestingly, the 4 participants who had complete clinical cure had baseline cultures positive for either T mentagrophytes or C parapsilosis. Most patients were content with the treatment, as 9 participants stated that they were very satisfied and 9 stated that they were satisfied. The average ratio of affected to total nail area declined from 63% at screening to 41% at the end of the study (P<.001). No adverse effects were reported with study drug.⁴⁰

NCR Lacquer

Background

Resins are natural products derived from coniferous trees and are believed to protect trees against insects and microbial pathogens.⁴¹ Natural coniferous resin derived from the Norway spruce tree (Picea abies) mixed with boiled animal fat or butter has been used topically for centuries in Finland and Sweden to treat infections and wounds.^42-44 The activity of NCR has been studied against a wide range of microbes, demonstrating broad-spectrum antimicrobial activity against both gram-positive bacteria and fungi.^45-48 There are 2 published clinical trials evaluating NCR in the treatment of onychomycosis.^49,50

In Vitro Data

Natural coniferous resin has shown antifungal activity against T mentagrophytes, Trichophyton tonsurans, and T rubrum in vitro, which was demonstrated using medicated disks of resin on petri dishes inoculated with these organisms.⁴⁶ In another study, the authors evaluated the antifungal activity of NCR against human pathogenic fungi and yeasts using agar plate diffusion tests and showed that the resin had antifungal activity against Trichophyton species but not against Fusarium and most Candida species. Electron microscopy of T mentagrophytes exposed to NCR showed that all cells were dead inside the inhibition zone, with striking changes seen in the hyphal cell walls, while fungal cells outside the inhibition zone were morphologically normal.⁴⁷ In another report, utilizing the European Pharmacopoeia challenge test, NCR was highly effective against gram-positive and gram-negative bacteria as well as C albicans.⁴²

Clinical Trials

In one preliminary observational and prospective clinical trial, 15 participants with clinical and mycologic evidence of onychomycosis were instructed to apply NCR lacquer once daily for 9 months with a 4-week washout period, with the primary outcome measures being clinical and mycologic cure.⁴⁹ Thirteen (87%) enrolled participants were male and the average age was 65 years (age range, 37–80 years). The DLSO subtype was present in 9 (60%) participants. The mycologic cure rate at the end of the study was 65% (95% CI, 42%-87%), and none achieved clinical cure, but 6 participants showed some improvement in the appearance of the nail.⁴⁹

The second trial was a prospective, controlled, investigator-blinded study of 73 patients with clinical and mycologic evidence of toenail onychomycosis who were randomized to receive NCR 30%, amorolfine lacquer 5%, or 250 mg oral terbinafine.⁵⁰ The primary end point was mycologic cure at 10 months, and secondary end points were clinical efficacy, cost-effectiveness, and patient compliance. Clinical efficacy was based on the proximal linear growth of healthy nail and was classified as unchanged, partial, or complete. Partial responses were described as substantial decreases in onycholysis, subungual hyperkeratosis, and streaks. A complete response was defined as a fully normal appearance of the toenail. Most patients were male in the NCR (91% [21/23]), amorolfine (80% [20/25]), and terbinafine (68% [17/25]) groups; the average ages were 64, 63, and 64 years, respectively. Trichophyton rubrum was cultured most often in all 3 groups: NCR, 87% (20/23); amorolfine, 96% (24/25); and terbinafine, 84% (21/25). The remaining cases were from T mentagrophytes. A summary of the results is shown in Table 2. Patient compliance was 100% in all except 1 patient in the amorolfine treatment group with moderate compliance. There were no adverse events, except for 2 in the terbinafine group: diarrhea and rash.⁵⁰

AP Extract

Background

Ageratina pichinchensis, a member of the Asteraceae family, has been used historically in Mexico for fungal infections of the skin.^51,52 Fresh or dried leaves were extracted with alcohol and the product was administered topically onto damaged skin without considerable skin irritation.⁵³ Multiple studies have demonstrated that AP extract has in vitro antifungal activity along with other members of the Asteraceae family.^54-56 There also is evidence from clinical trials that AP extract is effective against superficial dermatophyte infections such as tinea pedis.⁵⁷ Given the positive antifungal in vitro data, the potential use of this agent was investigated for onychomycosis treatment.^53,58

In Vitro Data

The antifungal properties of the Asteraceae family have been tested in several in vitro experiments. Eupatorium aschenbornianum, described as synonymous with A pichinchensis,⁵⁹ was found to be most active against the dermatophytes T rubrum and T mentagrophytes with MICs of 0.3 and 0.03 mg/mL, respectively.⁵⁴ It is thought that the primary antimycotic activity is due to encecalin, an acetylchromene compound that was identified in other plants from the Asteraceae family and has activity against dermatophytes.⁵⁵ In another study, Ageratum houstanianum Mill, a comparable member of the Asteraceae family, had fungitoxic activity against T rubrum and C albicans isolated from nail infections.⁵⁶

Clinical Trials

A double-blind controlled trial was performed on 110 patients with clinical and mycologic evidence of mild to moderate toenail onychomycosis randomized to treatment with AP lacquer or ciclopirox lacquer 8% (control).⁵⁸ Primary end points were clinical effectiveness (completely normal nails) and mycologic cure. Patients were instructed to apply the lacquer once every third day during the first month, twice a week for the second month, and once a week for 16 weeks, with removal of the lacquer weekly. Demographics were similar between the AP lacquer and control groups, with mean ages of 44.6 and 46.5 years, respectively; women made up 74.5% and 67.2%, respectively, of each treatment group, with most patients having a 2- to 5-year history of disease (41.8% and 40.1%, respectively).⁵⁸ A summary of the data is shown in Table 3. No severe side effects were documented, but minimal nail fold skin pain was reported in 3 patients in the control group in the first week, resolving later in the trial.⁵⁸

A follow-up study was performed to determine the optimal concentration of AP lacquer for the treatment of onychomycosis.⁵³ One hundred twenty-two patients aged 19 to 65 years with clinical and mycologic evidence of mild to moderate DLSO were randomized to receive 12.6% or 16.8% AP lacquer applied once daily to the affected nails for 6 months. The nails were graded as healthy, mild, or moderately affected before and after treatment. There were no significant differences in demographics between the 2 treatment groups, and 77% of patients were women with a median age of 47 years. There were no significant side effects from either concentration of AP lacquer.⁵³

Ozonized Sunflower Oil

Background

Ozonized sunflower oil is derived by reacting ozone (O₃) with sunflower plant (Helianthus annuus) oil to form a petroleum jelly–like material.⁶⁰ It was originally shown to have antibacterial properties in vitro,⁶¹ and further studies have confirmed these findings and demonstrated anti-inflammatory, wound healing, and antifungal properties.^62-64 A formulation of ozonized sunflower oil used in Cuba is clinically indicated for the treatment of tinea pedis and impetigo.⁶⁵ The clinical efficacy of this product has been evaluated in a clinical trial for the treatment of onychomycosis.⁶⁵

In Vitro Data

A compound made up of 30% ozonized sunflower oil with 0.5% of α-lipoic acid was found to have antifungal activity against C albicans using the disk diffusion method, in addition to other bacterial organisms. The MIC values ranged from 2.0 to 3.5 mg/mL.⁶² Another study was designed to evaluate the in vitro antifungal activity of this formulation on samples cultured from patients with onychomycosis using the disk diffusion method. They found inhibition of growth of C albicans, C parapsilosis, and Candida tropicalis, which was inferior to amphotericin B, ketoconazole, fluconazole, and itraconazole.⁶⁴

Clinical Trial

A single-blind, controlled, phase 3 study was performed on 400 patients with clinical and mycologic evidence of onychomycosis. Patients were randomized to treatment with an ozonized sunflower oil solution or ketoconazole cream 2% applied to affected nails twice daily for 3 months, with filing and massage of the affected nails upon application of treatment.⁶⁵ Cured was defined as mycologic cure in addition to a healthy appearing nail, improved as an increase in healthy appearing nail in addition to a decrease in symptoms (ie, paresthesia, pain, itching) but positive mycological testing, same as no clinical change in appearance with positive mycological findings, and worse as increasing diseased nail involvement in the presence of positive mycological findings. Demographics were similar between groups with a mean age of 35 years. Men accounted for 80% of the study population, and 65% of the study population was white. The mean duration of disease was 30 months. They also reported on a 1-year follow-up, with 2.8% of patients in the ozonized sunflower oil solution group and 37.0% of patients in the ketoconazole group describing relapses. Trichophyton rubrum and C albicans were cultured from these patients.⁶⁵

Comment

Due to the poor efficacy, long-term treatment courses, inability to use nail polish, and high cost associated with many FDA-approved topical treatments, along with the systemic side effects, potential for drug-drug interactions, and cost associated with many oral therapies approved for onychomycosis, there has been a renewed interest in natural remedies and OTC treatments. Overall, TTO, TCS, NCR, AP extract, and ozonized sunflower oil have shown efficacy in vitro against some dermatophytes, nondermatophytes, and molds responsible for onychomycosis. One or more clinical trials were performed with each of these agents for the treatment of onychomycosis. They were mostly small pilot studies, and due to differences in trial design, the results cannot be compared with each other or with currently FDA-approved treatments. We can conclude that because adverse events were rare with all of these therapies—most commonly skin irritation or mild skin pain—they exhibit good safety.

For TTO, there was no statistical difference between the clotrimazole and TTO treatment groups in mycologic cure, clinical assessment, or patient subjective assessment of the nails.²⁹ Although there was an 80% complete cure in the butenafine and TTO group, it was 0% in the TTO group at week 36.³⁰ Trial design, longer treatment periods, incorporation into nanocapsules, or combination treatment with other antifungal agents may influence our future use of TTO for onychomycosis, but based on the present data we cannot recommend this treatment in clinical practice.

With TCS, 27.8% of participants had a mycologic cure and 22.2% had complete clinical cure.⁴⁰ Although it is difficult to draw firm conclusions from this small pilot study, there may be some benefit to treating toenail onychomycosis due to T mentagrophytes or C parapsilosis with TCS but no benefit in treating onychomycosis due to T rubrum, the more common cause of onychomycosis. Limitations of this study were lack of a placebo group, small sample size, wide variety of represented pathogens that may not be representative of the true population, and lack of stratification by baseline severity or involvement of nail. A larger randomized controlled clinical trial would be necessary to confirm the results of this small study and make formal recommendations.

In one clinical trial with NCR, mycologic cure was 65% at the end of the study.⁴⁹ No participants achieved clinical cure, but 6 participants showed some improvement in the appearance of the nail. Because this study was small (N=15), it is difficult to draw firm conclusions.⁴⁹ In another study with NCR, mycologic cure rates with NCR, amorolfine, and terbinafine were 13%, 8%, and 56%, respectively. Based on these results, NCR has similar antifungal efficacy to amorolfine but was inferior to oral terbinafine.⁵⁰ A larger randomized controlled clinical trial with more homogenous and less severely affected patients and longer treatment periods would be necessary to confirm the results of these small studies and make formal recommendations.

Because there were no significant differences in clinical effectiveness of mycologic cure rates between AP lacquer 10% and ciclopirox lacquer 8% in one clinical trial,⁵⁸ AP does not seem to be more effective than at least one of the current FDA-approved topical treatments; however, because AP lacquer 16.8% was shown to be more effective than AP lacquer 12.6% in one onychomycosis clinical trial, using higher concentrations of AP may yield better results in future trials.⁵³

One trial comparing ozonized sunflower oil to ketoconazole cream 2% showed 90.5% and 13.5% cure rates, respectively.⁶⁵ Although there is good in vitro antifungal activity and a clinical trial showing efficacy using ozonized sunflower oil for the treatment of onychomycosis, confirmatory studies are necessary before we can recommend this OTC treatment to our patients. Specifically, we will get the most data from large randomized controlled trials with strict inclusion/exclusion and efficacy criteria.

Conclusion

Over-the-counter and natural remedies may be an emerging area of research in the treatment of onychomycosis. This review summarizes the laboratory data and clinical trials on several of these agents and, when available, compares their clinical and mycologic efficacy with FDA-approved therapies. Shortcomings of some of these studies include a small study population, lack of adequate controls, nonstandardized mycologic testing, and abbreviated posttreatment evaluation times. It may be concluded that these products have varying degrees of efficacy and appear to be safe in the studies cited; however, at present, we cannot recommend any of them to our patients until there are larger randomized clinical trials with appropriate controls demonstrating their efficacy.

Onychomycosis is a fungal infection of the nail unit by dermatophytes, yeasts, and nondermatophyte molds. It is characterized by a white or yellow discoloration of the nail plate; hyperkeratosis of the nail bed; distal detachment of the nail plate from its bed (onycholysis); and nail plate dystrophy, including thickening, crumbling, and ridging. Onychomycosis is an important problem, representing 30% of all superficial fungal infections and an estimated 50% of all nail diseases.¹ Reported prevalence rates of onychomycosis in the United States and worldwide are varied, but the mean prevalence based on population-based studies in Europe and North America is estimated to be 4.3%.² It is more common in older individuals, with an incidence rate of 20% in those older than 60 years and 50% in those older than 70 years.³ Onychomycosis is more common in patients with diabetes and 1.9 to 2.8 times higher than the general population.⁴ Dermatophytes are responsible for the majority of cases of onychomycosis, particularly Trichophyton rubrum and Trichophyton mentagrophytes.⁵

Onychomycosis is divided into different subtypes based on clinical presentation, which in turn are characterized by varying infecting organisms and prognoses. The subtypes of onychomycosis are distal and lateral subungual (DLSO), proximal subungual, superficial, endonyx, mixed pattern, total dystrophic, and secondary. Distal and lateral subungual onychomycosis are by far the most common presentation and begins when the infecting organism invades the hyponychium and distal or lateral nail bed. Trichophyton rubrum is the most common organism and T mentagrophytes is second, but Candida parapsilosis and Candida albicans also are possibilities. Proximal subungual onychomycosis is far less frequent than DLSO and is usually caused by T rubrum. The fungus invades the proximal nail folds and penetrates the newly growing nail plate.⁶ This pattern is more common in immunosuppressed patients and should prompt testing for human immunodeficiency virus.⁷ Total dystrophic onychomycosis is the end stage of fungal nail plate invasion, may follow DLSO or proximal subungual onychomycosis, and is difficult to treat.⁶

Onychomycosis causes pain, paresthesia, and difficulty with ambulation.⁸ In patients with peripheral neuropathy and vascular problems, including diabetes, onychomycosis can increase the risk for foot ulcers, with amputation in severe cases.⁹ Patients also may present with aesthetic concerns that may impact their quality of life.¹⁰

Given the effect on quality of life along with medical risks associated with onychomycosis, a safe and successful treatment modality with a low risk of recurrence is desirable. Unfortunately, treatment of nail fungus is quite challenging for a number of reasons. First, the thickness of the nail and/or the fungal mass may be a barrier to the delivery of topical and systemic drugs at the source of the infection. In addition, the nail plate does not have intrinsic immunity. Also, recurrence after treatment is common due to residual hyphae or spores that were not previously eliminated.¹¹ Finally, many topical medications require long treatment courses, which may limit patient compliance, especially in patients who want to use nail polish for cosmesis or camouflage.

Currently Approved Therapies for Onychomycosis

Several definitions are needed to better interpret the results of onychomycosis clinical trials. Complete cure is defined as a negative potassium hydroxide preparation and negative fungal culture with a completely normal appearance of the nail. Mycological cure is defined as potassium hydroxide microscopy and fungal culture negative. Clinical cure is stated as 0% nail plate involvement but at times is reported as less than 5% and less than 10% involvement.

Terbinafine and itraconazole are the only US Food and Drug Administration (FDA)–approved systemic therapies, and ciclopirox, efinaconazole, and tavaborole are the only FDA-approved topicals. Advantages of systemic agents generally are higher cure rates and shorter treatment courses, thus better compliance. Disadvantages include greater incidence of systemic side effects and drug-drug interactions as well as the need for laboratory monitoring. Pros of topical therapies are low potential for adverse effects, no drug-drug interactions, and no monitoring of blood work. Cons include lower efficacy, long treatment courses, and poor patient compliance.

Terbinafine, an allylamine, taken orally once daily (250 mg) for 12 weeks for toenails and 6 weeks for fingernails currently is the preferred systemic treatment of onychomycosis, with complete cure rates of 38% and 59% and mycological cure rates of 70% and 79% for toenails and fingernails, respectively.¹² Itraconazole, an azole, is dosed orally at 200 mg daily for 3 months for toenails, with a complete cure rate of 14% and mycological cure rate of 54%.¹³ For fingernail onychomycosis only, itraconazole is dosed at 200 mg twice daily for 1 week, followed by a treatment-free period of 3 weeks, and then another 1-week course at thesame dose. The complete cure rate is 47% and the mycological cure is 61% for this pulse regimen.¹³

Ciclopirox is a hydroxypyridone and the 8% nail lacquer formulation was approved in 1999, making it the first topical medication to gain FDA approval for the treatment of toenail onychomycosis. Based on 2 clinical trials, complete cure rates for toenails are 5.5% and 8.5% and mycological cure rates are 29% and 36% at 48 weeks with removal of residual lacquer and debridement.¹⁴Efinaconazole is an azole and the 10% solution was FDA approved for the treatment of toenail onychomycosis in 2014.¹⁵ In 2 clinical trials, complete cure rates were 17.8% and 15.2% and mycological cure rates were 55.2% and 53.4% with once daily toenail application for 48 weeks.¹⁶ Tavaborole is a benzoxaborole and the 5% solution also was approved for the treatment of toenail onychomycosis in 2014.¹⁷ Two clinical trials reported complete cure rates of 6.5% and 9.1% and mycological cure rates of 31.1% and 35.9% with once daily toenail application for 48 weeks.¹⁸

Given the poor efficacy, systemic side effects, potential for drug-drug interactions, long-term treatment courses, and cost associated with current systemic and/or topical treatments, there has been a renewed interest in natural remedies and over-the-counter (OTC) therapies for onychomycosis. This review summarizes the in vitro and in vivo data, mechanisms of action, and clinical efficacy of various natural and OTC agents for the treatment of onychomycosis. Specifically, we summarize the data on tea tree oil (TTO), a popular topical cough suppressant (TCS), natural coniferous resin (NCR) lacquer, Ageratina pichinchensis (AP) extract, and ozonized sunflower oil.

Tea Tree Oil

Background

Tea tree oil is a volatile oil whose medicinal use dates back to the early 20th century when the Bundjabung aborigines of North and New South Wales extracted TTO from the dried leaves of the Melaleuca alternifolia plant and used it to treat superficial wounds.¹⁹ Tea tree oil has been shown to be an effective treatment of tinea pedis,²⁰ and it is widely used in Australia as well as in Europe and North America.²¹ Tea tree oil also has been investigated as an antifungal agent for the treatment of onychomycosis, both in vitro^22-28 and in clinical trials.^29,30

In Vitro Data

Because TTO is composed of more than 100 active components,²³ the antifungal activity of these individual components was investigated against 14 fungal isolates, including C albicans, T mentagrophytes, and Aspergillus species. The minimum inhibitory concentration (MIC) for α-pinene was less than 0.004% for T mentagrophytes and the components with the greatest MIC and minimum fungicidal concentration for the fungi tested were terpinen-4-ol and α-terpineol, respectively.²² The antifungal activity of TTO also was tested using disk diffusion assay experiments with 58 clinical isolates of fungi including C albicans, T rubrum, T mentagrophytes, and Aspergillus niger.²⁴ Tea tree oil was most effective at inhibiting T rubrum followed by T mentagrophytes,²⁴ which are the 2 most common etiologies of onychomycosis.⁵ In another report, the authors determined the MIC of TTO utilizing 4 different experiments with T rubrum as the infecting organism. Because TTO inhibited the growth of T rubrum at all concentrations greater than 0.1%, they found that the MIC was 0.1%.²⁵ Given the lack of adequate nail penetration of most topical therapies, TTO in nanocapsules (TTO-NC), TTO nanoemulsions, and normal emulsions were tested in vitro for their ability to inhibit the growth of T rubrum inoculated into nail shavings. Colony growth decreased significantly within the first week of treatment, with TTO-NC showing maximum efficacy (P<.001). This study showed that TTO, particularly TTO-NC, was effective in inhibiting the growth of T rubrum in vitro and that using nanocapsule technology may increase nail penetration and bioavailability.³¹

Much of what we know about TTO’s antifungal mechanism of action comes from experiments involving C albicans. To date, it has not been studied in T rubrum or T mentagrophytes, the 2 most common etiologies of onychomycosis.⁵ In C albicans, TTO causes altered permeability of plasma membranes,³² dose-dependent alteration of respiration,³³ decreased glucose-induced acidification of media surrounding fungi,³² and reversible inhibition of germ tube formation.^19,34

Clinical Trials

A randomized, double-blind, multicenter trial was performed on 117 patients with culture-proven DLSO who were randomized to receive TTO 100% or clotrimazole solution 1% applied twice daily to affected toenails for 6 months.²⁹ Primary outcome measures were mycologic cure, clinical assessment, and patient subjective assessment (Table 1). There were no statistical differences between the 2 treatment groups. Erythema and irritation were the most common adverse reactions occurring in 7.8% (5/64) of the TTO group.²⁹

Another study was a double-blind, placebo-controlled trial involving 60 patients with clinical and mycologic evidence of DLSO who were randomized to treatment with a cream containing butenafine hydrochloride 2% and TTO 5% (n=40) or a control cream containing only TTO (n=20), with active treatment for 8 weeks and final follow-up at 36 weeks.³⁰ Patients were instructed to apply the cream 3 times daily under occlusion for 8 weeks and the nail was debrided between weeks 4 and 6 if feasible. If the nail could not be debrided after 8 weeks, it was considered resistant to treatment. At the end of the study, the complete cure rate was 80% in the active group compared to 0% in the placebo group (P<.0001), and the mean time to complete healing with progressive nail growth was 29 weeks. There were no adverse effects in the placebo group, but 4 patients in the active group had mild skin inflammation.³⁰

Topical Cough Suppressant

Background

Topical cough suppressants, which are made up of several natural ingredients, are OTC ointments for adults and children 2 years and older that are indicated as cough suppressants when applied to the chest and throat and as relief of mild muscle and joint pains.³⁵ The active ingredients are camphor 4.8%, eucalyptus oil 1.2%, and menthol 2.6%, while the inactive ingredients are cedarleaf oil, nutmeg oil, petrolatum, thymol, and turpentine oil.³⁵ Some of the active and inactive ingredients in TCSs have shown efficacy against dermatophytes in vitro,^36-38 and although they are not specifically indicated for onychomycosis, they have been popularized as home remedies for fungal nail infections.^36,39 A TCS has been evaluated for its efficacy for the treatment of onychomycosis in one clinical trial.⁴⁰

In Vitro Data

An in vitro study was performed to evaluate the antifungal activity of the individual and combined components of TCS on 16 different dermatophytes, nondermatophytes, and molds. The zones of inhibition against these organisms were greatest for camphor, menthol, thymol, and eucalyptus oil. Interestingly, there were large zones of inhibition and a synergistic effect when a mixture of components was used against T rubrum and T mentagrophytes.³⁶ The in vitro activity of thymol, a component of TCS, was tested against Candida species.³⁷ The essential oil subtypes Thymus vulgaris and Thymus zygis (subspecies zygis) showed similar antifungal activity, which was superior to Thymus mastichina, and all 3 compounds had similar MIC and minimal lethal concentration values. The authors showed that the antifungal mechanism was due to cell membrane damage and inhibition of germ tube formation.³⁷ It should be noted that Candida species are less common causes of onychomycosis, and it is not known whether this data is applicable to T rubrum. In another study, the authors investigated the antifungal activity of Thymus pulegioides and found that MIC ranged from 0.16 to 0.32 μL/mL for dermatophytes and Aspergillus strains and 0.32 to 0.64 μL/mL for Candida species. When an essential oil concentration of 0.08 μL/mL was used against T rubrum, ergosterol content decreased by 70 %, indicating that T pulegioides inhibits ergosterol biosynthesis in T rubrum.³⁸

Clinical Observations and Clinical Trial

There is one report documenting the clinical observations on a group of patients with a clinical diagnosis of onychomycosis who were instructed to apply TCS to affected nail(s) once daily.³⁶ Eighty-five charts were reviewed (mean age, 77 years), and although follow-up was not complete or standardized, the following data were reported: 32 (38%) cleared their fungal infection, 21 (25%) had no record of change but also no record of compliance, 19 (22%) had only 1 documented follow-up visit, 9 (11%) reported they did not use the treatment, and 4 (5%) did not return for a follow-up visit. Of the 32 patients whose nails were cured, 3 (9%) had clearance within 5 months, 8 (25%) within 7 months, 11 (34%) within 9 months, 4 (13%) within 11 months, and 6 (19%) within 16 months.³⁶

A small pilot study was performed to evaluate the efficacy of daily application of TCS in the treatment of onychomycosis in patients 18 years and older with at least 1 great toenail affected.⁴⁰ The primary end points were mycologic cure at 48 weeks and clinical cure at the end of the study graded as complete, partial, or no change. The secondary end point was patient satisfaction with the appearance of the affected nail at 48 weeks. Eighteen participants completed the study; 55% (10/18) were male, with an average age of 51 years (age range, 30–85 years). The mean initial amount of affected nail was 62% (range, 16%–100%), and cultures included dermatophytes, nondermatophytes, and molds. With TCS treatment, 27.8% (5/18) showed mycologic cure of which 4 (22.2%) had a complete clinical cure. Ten participants (55.6%) had partial clinical cure and 3 (16.7%) had no clinical improvement. Interestingly, the 4 participants who had complete clinical cure had baseline cultures positive for either T mentagrophytes or C parapsilosis. Most patients were content with the treatment, as 9 participants stated that they were very satisfied and 9 stated that they were satisfied. The average ratio of affected to total nail area declined from 63% at screening to 41% at the end of the study (P<.001). No adverse effects were reported with study drug.⁴⁰

NCR Lacquer

Background

Resins are natural products derived from coniferous trees and are believed to protect trees against insects and microbial pathogens.⁴¹ Natural coniferous resin derived from the Norway spruce tree (Picea abies) mixed with boiled animal fat or butter has been used topically for centuries in Finland and Sweden to treat infections and wounds.^42-44 The activity of NCR has been studied against a wide range of microbes, demonstrating broad-spectrum antimicrobial activity against both gram-positive bacteria and fungi.^45-48 There are 2 published clinical trials evaluating NCR in the treatment of onychomycosis.^49,50

In Vitro Data

Natural coniferous resin has shown antifungal activity against T mentagrophytes, Trichophyton tonsurans, and T rubrum in vitro, which was demonstrated using medicated disks of resin on petri dishes inoculated with these organisms.⁴⁶ In another study, the authors evaluated the antifungal activity of NCR against human pathogenic fungi and yeasts using agar plate diffusion tests and showed that the resin had antifungal activity against Trichophyton species but not against Fusarium and most Candida species. Electron microscopy of T mentagrophytes exposed to NCR showed that all cells were dead inside the inhibition zone, with striking changes seen in the hyphal cell walls, while fungal cells outside the inhibition zone were morphologically normal.⁴⁷ In another report, utilizing the European Pharmacopoeia challenge test, NCR was highly effective against gram-positive and gram-negative bacteria as well as C albicans.⁴²

Clinical Trials

In one preliminary observational and prospective clinical trial, 15 participants with clinical and mycologic evidence of onychomycosis were instructed to apply NCR lacquer once daily for 9 months with a 4-week washout period, with the primary outcome measures being clinical and mycologic cure.⁴⁹ Thirteen (87%) enrolled participants were male and the average age was 65 years (age range, 37–80 years). The DLSO subtype was present in 9 (60%) participants. The mycologic cure rate at the end of the study was 65% (95% CI, 42%-87%), and none achieved clinical cure, but 6 participants showed some improvement in the appearance of the nail.⁴⁹

The second trial was a prospective, controlled, investigator-blinded study of 73 patients with clinical and mycologic evidence of toenail onychomycosis who were randomized to receive NCR 30%, amorolfine lacquer 5%, or 250 mg oral terbinafine.⁵⁰ The primary end point was mycologic cure at 10 months, and secondary end points were clinical efficacy, cost-effectiveness, and patient compliance. Clinical efficacy was based on the proximal linear growth of healthy nail and was classified as unchanged, partial, or complete. Partial responses were described as substantial decreases in onycholysis, subungual hyperkeratosis, and streaks. A complete response was defined as a fully normal appearance of the toenail. Most patients were male in the NCR (91% [21/23]), amorolfine (80% [20/25]), and terbinafine (68% [17/25]) groups; the average ages were 64, 63, and 64 years, respectively. Trichophyton rubrum was cultured most often in all 3 groups: NCR, 87% (20/23); amorolfine, 96% (24/25); and terbinafine, 84% (21/25). The remaining cases were from T mentagrophytes. A summary of the results is shown in Table 2. Patient compliance was 100% in all except 1 patient in the amorolfine treatment group with moderate compliance. There were no adverse events, except for 2 in the terbinafine group: diarrhea and rash.⁵⁰

AP Extract

Background

Ageratina pichinchensis, a member of the Asteraceae family, has been used historically in Mexico for fungal infections of the skin.^51,52 Fresh or dried leaves were extracted with alcohol and the product was administered topically onto damaged skin without considerable skin irritation.⁵³ Multiple studies have demonstrated that AP extract has in vitro antifungal activity along with other members of the Asteraceae family.^54-56 There also is evidence from clinical trials that AP extract is effective against superficial dermatophyte infections such as tinea pedis.⁵⁷ Given the positive antifungal in vitro data, the potential use of this agent was investigated for onychomycosis treatment.^53,58

In Vitro Data

The antifungal properties of the Asteraceae family have been tested in several in vitro experiments. Eupatorium aschenbornianum, described as synonymous with A pichinchensis,⁵⁹ was found to be most active against the dermatophytes T rubrum and T mentagrophytes with MICs of 0.3 and 0.03 mg/mL, respectively.⁵⁴ It is thought that the primary antimycotic activity is due to encecalin, an acetylchromene compound that was identified in other plants from the Asteraceae family and has activity against dermatophytes.⁵⁵ In another study, Ageratum houstanianum Mill, a comparable member of the Asteraceae family, had fungitoxic activity against T rubrum and C albicans isolated from nail infections.⁵⁶

Clinical Trials

A double-blind controlled trial was performed on 110 patients with clinical and mycologic evidence of mild to moderate toenail onychomycosis randomized to treatment with AP lacquer or ciclopirox lacquer 8% (control).⁵⁸ Primary end points were clinical effectiveness (completely normal nails) and mycologic cure. Patients were instructed to apply the lacquer once every third day during the first month, twice a week for the second month, and once a week for 16 weeks, with removal of the lacquer weekly. Demographics were similar between the AP lacquer and control groups, with mean ages of 44.6 and 46.5 years, respectively; women made up 74.5% and 67.2%, respectively, of each treatment group, with most patients having a 2- to 5-year history of disease (41.8% and 40.1%, respectively).⁵⁸ A summary of the data is shown in Table 3. No severe side effects were documented, but minimal nail fold skin pain was reported in 3 patients in the control group in the first week, resolving later in the trial.⁵⁸

A follow-up study was performed to determine the optimal concentration of AP lacquer for the treatment of onychomycosis.⁵³ One hundred twenty-two patients aged 19 to 65 years with clinical and mycologic evidence of mild to moderate DLSO were randomized to receive 12.6% or 16.8% AP lacquer applied once daily to the affected nails for 6 months. The nails were graded as healthy, mild, or moderately affected before and after treatment. There were no significant differences in demographics between the 2 treatment groups, and 77% of patients were women with a median age of 47 years. There were no significant side effects from either concentration of AP lacquer.⁵³

Ozonized Sunflower Oil

Background

Ozonized sunflower oil is derived by reacting ozone (O₃) with sunflower plant (Helianthus annuus) oil to form a petroleum jelly–like material.⁶⁰ It was originally shown to have antibacterial properties in vitro,⁶¹ and further studies have confirmed these findings and demonstrated anti-inflammatory, wound healing, and antifungal properties.^62-64 A formulation of ozonized sunflower oil used in Cuba is clinically indicated for the treatment of tinea pedis and impetigo.⁶⁵ The clinical efficacy of this product has been evaluated in a clinical trial for the treatment of onychomycosis.⁶⁵

In Vitro Data

A compound made up of 30% ozonized sunflower oil with 0.5% of α-lipoic acid was found to have antifungal activity against C albicans using the disk diffusion method, in addition to other bacterial organisms. The MIC values ranged from 2.0 to 3.5 mg/mL.⁶² Another study was designed to evaluate the in vitro antifungal activity of this formulation on samples cultured from patients with onychomycosis using the disk diffusion method. They found inhibition of growth of C albicans, C parapsilosis, and Candida tropicalis, which was inferior to amphotericin B, ketoconazole, fluconazole, and itraconazole.⁶⁴

Clinical Trial

A single-blind, controlled, phase 3 study was performed on 400 patients with clinical and mycologic evidence of onychomycosis. Patients were randomized to treatment with an ozonized sunflower oil solution or ketoconazole cream 2% applied to affected nails twice daily for 3 months, with filing and massage of the affected nails upon application of treatment.⁶⁵ Cured was defined as mycologic cure in addition to a healthy appearing nail, improved as an increase in healthy appearing nail in addition to a decrease in symptoms (ie, paresthesia, pain, itching) but positive mycological testing, same as no clinical change in appearance with positive mycological findings, and worse as increasing diseased nail involvement in the presence of positive mycological findings. Demographics were similar between groups with a mean age of 35 years. Men accounted for 80% of the study population, and 65% of the study population was white. The mean duration of disease was 30 months. They also reported on a 1-year follow-up, with 2.8% of patients in the ozonized sunflower oil solution group and 37.0% of patients in the ketoconazole group describing relapses. Trichophyton rubrum and C albicans were cultured from these patients.⁶⁵

Comment

Due to the poor efficacy, long-term treatment courses, inability to use nail polish, and high cost associated with many FDA-approved topical treatments, along with the systemic side effects, potential for drug-drug interactions, and cost associated with many oral therapies approved for onychomycosis, there has been a renewed interest in natural remedies and OTC treatments. Overall, TTO, TCS, NCR, AP extract, and ozonized sunflower oil have shown efficacy in vitro against some dermatophytes, nondermatophytes, and molds responsible for onychomycosis. One or more clinical trials were performed with each of these agents for the treatment of onychomycosis. They were mostly small pilot studies, and due to differences in trial design, the results cannot be compared with each other or with currently FDA-approved treatments. We can conclude that because adverse events were rare with all of these therapies—most commonly skin irritation or mild skin pain—they exhibit good safety.

For TTO, there was no statistical difference between the clotrimazole and TTO treatment groups in mycologic cure, clinical assessment, or patient subjective assessment of the nails.²⁹ Although there was an 80% complete cure in the butenafine and TTO group, it was 0% in the TTO group at week 36.³⁰ Trial design, longer treatment periods, incorporation into nanocapsules, or combination treatment with other antifungal agents may influence our future use of TTO for onychomycosis, but based on the present data we cannot recommend this treatment in clinical practice.

With TCS, 27.8% of participants had a mycologic cure and 22.2% had complete clinical cure.⁴⁰ Although it is difficult to draw firm conclusions from this small pilot study, there may be some benefit to treating toenail onychomycosis due to T mentagrophytes or C parapsilosis with TCS but no benefit in treating onychomycosis due to T rubrum, the more common cause of onychomycosis. Limitations of this study were lack of a placebo group, small sample size, wide variety of represented pathogens that may not be representative of the true population, and lack of stratification by baseline severity or involvement of nail. A larger randomized controlled clinical trial would be necessary to confirm the results of this small study and make formal recommendations.

In one clinical trial with NCR, mycologic cure was 65% at the end of the study.⁴⁹ No participants achieved clinical cure, but 6 participants showed some improvement in the appearance of the nail. Because this study was small (N=15), it is difficult to draw firm conclusions.⁴⁹ In another study with NCR, mycologic cure rates with NCR, amorolfine, and terbinafine were 13%, 8%, and 56%, respectively. Based on these results, NCR has similar antifungal efficacy to amorolfine but was inferior to oral terbinafine.⁵⁰ A larger randomized controlled clinical trial with more homogenous and less severely affected patients and longer treatment periods would be necessary to confirm the results of these small studies and make formal recommendations.

Because there were no significant differences in clinical effectiveness of mycologic cure rates between AP lacquer 10% and ciclopirox lacquer 8% in one clinical trial,⁵⁸ AP does not seem to be more effective than at least one of the current FDA-approved topical treatments; however, because AP lacquer 16.8% was shown to be more effective than AP lacquer 12.6% in one onychomycosis clinical trial, using higher concentrations of AP may yield better results in future trials.⁵³

One trial comparing ozonized sunflower oil to ketoconazole cream 2% showed 90.5% and 13.5% cure rates, respectively.⁶⁵ Although there is good in vitro antifungal activity and a clinical trial showing efficacy using ozonized sunflower oil for the treatment of onychomycosis, confirmatory studies are necessary before we can recommend this OTC treatment to our patients. Specifically, we will get the most data from large randomized controlled trials with strict inclusion/exclusion and efficacy criteria.

Conclusion

Over-the-counter and natural remedies may be an emerging area of research in the treatment of onychomycosis. This review summarizes the laboratory data and clinical trials on several of these agents and, when available, compares their clinical and mycologic efficacy with FDA-approved therapies. Shortcomings of some of these studies include a small study population, lack of adequate controls, nonstandardized mycologic testing, and abbreviated posttreatment evaluation times. It may be concluded that these products have varying degrees of efficacy and appear to be safe in the studies cited; however, at present, we cannot recommend any of them to our patients until there are larger randomized clinical trials with appropriate controls demonstrating their efficacy.

In 1909, Sabouraud¹ published a report delineating the clinical subsets of a chronic fungal infection of the scalp known as favus. The rarest subset was termed favus papyroide and consisted of a thin, dry, gray, parchmentlike crust up to 5 cm in diameter. Hair shafts were described as piercing the crust, with the underlying skin exhibiting erythema, moisture, and erosions. Children were reported to be affected more often than adults.¹ Subsequent descriptions of patients with similar presentations have not appeared in the medical literature. In this case, an elderly woman with tinea capitis (TC) due to Trichophyton rubrum exhibited features of favus papyroide.

Case Report

An 87-year-old woman with a long history of actinic keratoses and nonmelanoma skin cancers presented to our dermatology clinic with numerous growths on the head, neck, and arms. The patient resided in a nursing home and had a history of hypertension, osteoarthritis, and mild to moderate dementia. Physical examination revealed a frail elderly woman in a wheelchair. Numerous actinic keratoses were noted on the arms and face. Examination of the scalp revealed a large, white-gray, palm-sized plaque on the crown (Figure 1) with 2 yellow, quarter-sized, hyperkeratotic nodules on the left temple and left parietal scalp. The differential diagnosis for the nodules on the temple and scalp included squamous cell carcinoma and hyperkeratotic actinic keratosis, and both lesions were biopsied. Histologically, they demonstrated pronounced hyperkeratosis and parakeratosis with numerous infiltrating neutrophils. The stratum malpighii exhibited focal atypia consistent with an actinic keratosis with areas of spongiosis and pustular folliculitis but no evidence of an invasive cutaneous malignancy. Periodic acid–Schiff stains were performed on both specimens and revealed numerous fungal hyphae within the stratum corneum (Figure 2) as well as evidence of a fungal folliculitis.

At a follow-up visit 2 weeks later, a portion of the hyperkeratotic material on the crown of the scalp was lifted free from the skin surface, removed with scissors, and submitted for histologic analysis and culture. The underlying skin exhibited substantial erythema and diffuse alopecia. The specimen consisted entirely of masses of hyperkeratotic and parakeratotic stratum corneum with numerous infiltrating neutrophils, cellular debris, and focal secondary bacterial colonization (Figure 3). Fungal hyphae and spores were readily demonstrated on Gomori methenamine-silver stain (Figure 4). A fungal culture from this material failed to demonstrate growth at 28 days. The organism was molecularly identified as T rubrum using the Sanger sequencing assay. The patient was treated with fluconazole 150 mg once daily for 3 weeks with eventual resolution of the plaque. The patient died approximately 3 months later (unrelated to her scalp infection).

Comment

Favus, or tinea favosa, is a chronic inflammatory dermatophyte infection of the scalp, less commonly involving the skin and nails.² The classic lesion is termed a scutulum or godet consisting of concave, cup-shaped, yellow crusts typically pierced by a single hair shaft.¹ With an increase in size, the scutula may become confluent. Alopecia commonly results and infected patients may exude a “cheesy” or “mousy” odor from the lesions.³ Sabouraud¹ delineated 3 clinical presentations of favus: (1) favus pityroide, the most common type consisting of a seborrheic dermatitis–like picture and scutula; (2) favus impetigoide, exhibiting honey-colored crusts reminiscent of impetigo but without appreciable scutula; and (3) favus papyroide, the rarest variant, demonstrating a dry, gray, parchmentlike crust pierced by hair shafts overlying an eroded erythematous scalp.

Favus usually is acquired in childhood or adolescence and often persists into adulthood.³ It is transmitted directly by hairs, infected keratinocytes, and fomites. Child-to-child transmission is much less common than other forms of TC.⁴ The responsible organism is almost always Trichophyton schoenleinii, with rare cases of Trichophyton violaceum, Trichophyton verrucosum, Trichophyton mentagrophytes var quinckeanum, Microsporum canis, and Microsporum gypseum having been reported.^2,5,6 This anthropophilic dermatophyte infects only humans, is capable of surviving in the same dwelling space for generations, and is believed to require prolonged exposure for transmission. Trichophyton schoenleinii was the predominant infectious cause of TC in eastern Europe in the 19th and early 20th centuries, but its incidence has dramatically declined in the last 50 years.⁷ A survey conducted in 1997 and published in 2001 of TC that was culture-positive for T schoenleinii in 19 European countries found only 3 cases among 3671 isolates (0.08%).⁸ Between 1980 and 2005, no cases were reported in the British Isles.⁹ Currently, favus generally is found in impoverished geographic regions with poor hygiene, malnutrition, and limited access to health care; however, endemic foci in Kentucky, Quebec, and Montreal have been reported in North America.¹⁰ Although favus rarely resolves spontaneously, T schoenleinii was eradicated in most of the world with the introduction of griseofulvin in 1958.⁷ Terbinafine and itraconazole are currently the drugs of choice for therapy.¹⁰

Tinea capitis is the most common fungal infection in children, with 1 in 20 US children displaying evidence of overt infection.¹¹ Infection in adults is rare and most affected patients typically display serious illnesses with concomitant immune compromise.¹² Only 3% to 5% of cases arise in patients older than 20 years.¹³ Adult hair appears to be relatively resistant to dermatophyte infection, probably from the fungistatic properties of long-chain fatty acids found in sebum.¹³ Tinea capitis in adults usually occurs in postmenopausal women, presumably from involution of sebaceous glands associated with declining estrogen levels. Patients typically exhibit erythematous scaly patches with central clearing, alopecia, varying degrees of inflammation, and few pustules, though exudative and heavily inflammatory lesions also have been described.¹⁴

In the current case, TC was not raised in the differential diagnosis. Regardless, given that scaly red patches and papules of the scalp may represent a dermatophyte infection in this patient population, clinicians are encouraged to consider this possibility. Transmission is by direct human-to-human contact and contact with objects containing fomites including brushes, combs, bedding, clothing, toys, furniture, and telephones.¹⁵ It is frequently spread among family members and classmates.¹⁶

Prior to World War II, most cases of TC in the United States were due to M canis, with Microsporum audouinii becoming more prevalent until the 1960s and 1970s when Trichophyton tonsurans began surging in incidence.^12,17 Currently, the latter organism is responsible for more than 95% of TC cases in the United States.¹⁸Microsporum canis is the main causative species in Europe but varies widely by country. In the Middle East and Africa, T violaceum is responsible for many infections.

Trichophyton rubrum–associated TC appears to be a rare occurrence. A global study in 1995 noted that less than 1% of TC cases were due to T rubrum infection, most having been described in emerging nations.¹² A meta-analysis of 9 studies from developed countries found only 9 of 10,145 cases of TC with a culture positive for T rubrum.¹⁴ In adults, infected patients typically exhibit either evidence of a concomitant fungal infection of the skin and/or nails or health conditions with impaired immunity, whereas in children, interfamilial spread appears more common.¹¹

In 1909, Sabouraud¹ published a report delineating the clinical subsets of a chronic fungal infection of the scalp known as favus. The rarest subset was termed favus papyroide and consisted of a thin, dry, gray, parchmentlike crust up to 5 cm in diameter. Hair shafts were described as piercing the crust, with the underlying skin exhibiting erythema, moisture, and erosions. Children were reported to be affected more often than adults.¹ Subsequent descriptions of patients with similar presentations have not appeared in the medical literature. In this case, an elderly woman with tinea capitis (TC) due to Trichophyton rubrum exhibited features of favus papyroide.

Case Report

An 87-year-old woman with a long history of actinic keratoses and nonmelanoma skin cancers presented to our dermatology clinic with numerous growths on the head, neck, and arms. The patient resided in a nursing home and had a history of hypertension, osteoarthritis, and mild to moderate dementia. Physical examination revealed a frail elderly woman in a wheelchair. Numerous actinic keratoses were noted on the arms and face. Examination of the scalp revealed a large, white-gray, palm-sized plaque on the crown (Figure 1) with 2 yellow, quarter-sized, hyperkeratotic nodules on the left temple and left parietal scalp. The differential diagnosis for the nodules on the temple and scalp included squamous cell carcinoma and hyperkeratotic actinic keratosis, and both lesions were biopsied. Histologically, they demonstrated pronounced hyperkeratosis and parakeratosis with numerous infiltrating neutrophils. The stratum malpighii exhibited focal atypia consistent with an actinic keratosis with areas of spongiosis and pustular folliculitis but no evidence of an invasive cutaneous malignancy. Periodic acid–Schiff stains were performed on both specimens and revealed numerous fungal hyphae within the stratum corneum (Figure 2) as well as evidence of a fungal folliculitis.

At a follow-up visit 2 weeks later, a portion of the hyperkeratotic material on the crown of the scalp was lifted free from the skin surface, removed with scissors, and submitted for histologic analysis and culture. The underlying skin exhibited substantial erythema and diffuse alopecia. The specimen consisted entirely of masses of hyperkeratotic and parakeratotic stratum corneum with numerous infiltrating neutrophils, cellular debris, and focal secondary bacterial colonization (Figure 3). Fungal hyphae and spores were readily demonstrated on Gomori methenamine-silver stain (Figure 4). A fungal culture from this material failed to demonstrate growth at 28 days. The organism was molecularly identified as T rubrum using the Sanger sequencing assay. The patient was treated with fluconazole 150 mg once daily for 3 weeks with eventual resolution of the plaque. The patient died approximately 3 months later (unrelated to her scalp infection).

Comment

Favus, or tinea favosa, is a chronic inflammatory dermatophyte infection of the scalp, less commonly involving the skin and nails.² The classic lesion is termed a scutulum or godet consisting of concave, cup-shaped, yellow crusts typically pierced by a single hair shaft.¹ With an increase in size, the scutula may become confluent. Alopecia commonly results and infected patients may exude a “cheesy” or “mousy” odor from the lesions.³ Sabouraud¹ delineated 3 clinical presentations of favus: (1) favus pityroide, the most common type consisting of a seborrheic dermatitis–like picture and scutula; (2) favus impetigoide, exhibiting honey-colored crusts reminiscent of impetigo but without appreciable scutula; and (3) favus papyroide, the rarest variant, demonstrating a dry, gray, parchmentlike crust pierced by hair shafts overlying an eroded erythematous scalp.

Favus usually is acquired in childhood or adolescence and often persists into adulthood.³ It is transmitted directly by hairs, infected keratinocytes, and fomites. Child-to-child transmission is much less common than other forms of TC.⁴ The responsible organism is almost always Trichophyton schoenleinii, with rare cases of Trichophyton violaceum, Trichophyton verrucosum, Trichophyton mentagrophytes var quinckeanum, Microsporum canis, and Microsporum gypseum having been reported.^2,5,6 This anthropophilic dermatophyte infects only humans, is capable of surviving in the same dwelling space for generations, and is believed to require prolonged exposure for transmission. Trichophyton schoenleinii was the predominant infectious cause of TC in eastern Europe in the 19th and early 20th centuries, but its incidence has dramatically declined in the last 50 years.⁷ A survey conducted in 1997 and published in 2001 of TC that was culture-positive for T schoenleinii in 19 European countries found only 3 cases among 3671 isolates (0.08%).⁸ Between 1980 and 2005, no cases were reported in the British Isles.⁹ Currently, favus generally is found in impoverished geographic regions with poor hygiene, malnutrition, and limited access to health care; however, endemic foci in Kentucky, Quebec, and Montreal have been reported in North America.¹⁰ Although favus rarely resolves spontaneously, T schoenleinii was eradicated in most of the world with the introduction of griseofulvin in 1958.⁷ Terbinafine and itraconazole are currently the drugs of choice for therapy.¹⁰

Tinea capitis is the most common fungal infection in children, with 1 in 20 US children displaying evidence of overt infection.¹¹ Infection in adults is rare and most affected patients typically display serious illnesses with concomitant immune compromise.¹² Only 3% to 5% of cases arise in patients older than 20 years.¹³ Adult hair appears to be relatively resistant to dermatophyte infection, probably from the fungistatic properties of long-chain fatty acids found in sebum.¹³ Tinea capitis in adults usually occurs in postmenopausal women, presumably from involution of sebaceous glands associated with declining estrogen levels. Patients typically exhibit erythematous scaly patches with central clearing, alopecia, varying degrees of inflammation, and few pustules, though exudative and heavily inflammatory lesions also have been described.¹⁴

In the current case, TC was not raised in the differential diagnosis. Regardless, given that scaly red patches and papules of the scalp may represent a dermatophyte infection in this patient population, clinicians are encouraged to consider this possibility. Transmission is by direct human-to-human contact and contact with objects containing fomites including brushes, combs, bedding, clothing, toys, furniture, and telephones.¹⁵ It is frequently spread among family members and classmates.¹⁶

Prior to World War II, most cases of TC in the United States were due to M canis, with Microsporum audouinii becoming more prevalent until the 1960s and 1970s when Trichophyton tonsurans began surging in incidence.^12,17 Currently, the latter organism is responsible for more than 95% of TC cases in the United States.¹⁸Microsporum canis is the main causative species in Europe but varies widely by country. In the Middle East and Africa, T violaceum is responsible for many infections.

Trichophyton rubrum–associated TC appears to be a rare occurrence. A global study in 1995 noted that less than 1% of TC cases were due to T rubrum infection, most having been described in emerging nations.¹² A meta-analysis of 9 studies from developed countries found only 9 of 10,145 cases of TC with a culture positive for T rubrum.¹⁴ In adults, infected patients typically exhibit either evidence of a concomitant fungal infection of the skin and/or nails or health conditions with impaired immunity, whereas in children, interfamilial spread appears more common.¹¹

In 1909, Sabouraud¹ published a report delineating the clinical subsets of a chronic fungal infection of the scalp known as favus. The rarest subset was termed favus papyroide and consisted of a thin, dry, gray, parchmentlike crust up to 5 cm in diameter. Hair shafts were described as piercing the crust, with the underlying skin exhibiting erythema, moisture, and erosions. Children were reported to be affected more often than adults.¹ Subsequent descriptions of patients with similar presentations have not appeared in the medical literature. In this case, an elderly woman with tinea capitis (TC) due to Trichophyton rubrum exhibited features of favus papyroide.

Case Report

An 87-year-old woman with a long history of actinic keratoses and nonmelanoma skin cancers presented to our dermatology clinic with numerous growths on the head, neck, and arms. The patient resided in a nursing home and had a history of hypertension, osteoarthritis, and mild to moderate dementia. Physical examination revealed a frail elderly woman in a wheelchair. Numerous actinic keratoses were noted on the arms and face. Examination of the scalp revealed a large, white-gray, palm-sized plaque on the crown (Figure 1) with 2 yellow, quarter-sized, hyperkeratotic nodules on the left temple and left parietal scalp. The differential diagnosis for the nodules on the temple and scalp included squamous cell carcinoma and hyperkeratotic actinic keratosis, and both lesions were biopsied. Histologically, they demonstrated pronounced hyperkeratosis and parakeratosis with numerous infiltrating neutrophils. The stratum malpighii exhibited focal atypia consistent with an actinic keratosis with areas of spongiosis and pustular folliculitis but no evidence of an invasive cutaneous malignancy. Periodic acid–Schiff stains were performed on both specimens and revealed numerous fungal hyphae within the stratum corneum (Figure 2) as well as evidence of a fungal folliculitis.

At a follow-up visit 2 weeks later, a portion of the hyperkeratotic material on the crown of the scalp was lifted free from the skin surface, removed with scissors, and submitted for histologic analysis and culture. The underlying skin exhibited substantial erythema and diffuse alopecia. The specimen consisted entirely of masses of hyperkeratotic and parakeratotic stratum corneum with numerous infiltrating neutrophils, cellular debris, and focal secondary bacterial colonization (Figure 3). Fungal hyphae and spores were readily demonstrated on Gomori methenamine-silver stain (Figure 4). A fungal culture from this material failed to demonstrate growth at 28 days. The organism was molecularly identified as T rubrum using the Sanger sequencing assay. The patient was treated with fluconazole 150 mg once daily for 3 weeks with eventual resolution of the plaque. The patient died approximately 3 months later (unrelated to her scalp infection).

Comment

Favus, or tinea favosa, is a chronic inflammatory dermatophyte infection of the scalp, less commonly involving the skin and nails.² The classic lesion is termed a scutulum or godet consisting of concave, cup-shaped, yellow crusts typically pierced by a single hair shaft.¹ With an increase in size, the scutula may become confluent. Alopecia commonly results and infected patients may exude a “cheesy” or “mousy” odor from the lesions.³ Sabouraud¹ delineated 3 clinical presentations of favus: (1) favus pityroide, the most common type consisting of a seborrheic dermatitis–like picture and scutula; (2) favus impetigoide, exhibiting honey-colored crusts reminiscent of impetigo but without appreciable scutula; and (3) favus papyroide, the rarest variant, demonstrating a dry, gray, parchmentlike crust pierced by hair shafts overlying an eroded erythematous scalp.

Favus usually is acquired in childhood or adolescence and often persists into adulthood.³ It is transmitted directly by hairs, infected keratinocytes, and fomites. Child-to-child transmission is much less common than other forms of TC.⁴ The responsible organism is almost always Trichophyton schoenleinii, with rare cases of Trichophyton violaceum, Trichophyton verrucosum, Trichophyton mentagrophytes var quinckeanum, Microsporum canis, and Microsporum gypseum having been reported.^2,5,6 This anthropophilic dermatophyte infects only humans, is capable of surviving in the same dwelling space for generations, and is believed to require prolonged exposure for transmission. Trichophyton schoenleinii was the predominant infectious cause of TC in eastern Europe in the 19th and early 20th centuries, but its incidence has dramatically declined in the last 50 years.⁷ A survey conducted in 1997 and published in 2001 of TC that was culture-positive for T schoenleinii in 19 European countries found only 3 cases among 3671 isolates (0.08%).⁸ Between 1980 and 2005, no cases were reported in the British Isles.⁹ Currently, favus generally is found in impoverished geographic regions with poor hygiene, malnutrition, and limited access to health care; however, endemic foci in Kentucky, Quebec, and Montreal have been reported in North America.¹⁰ Although favus rarely resolves spontaneously, T schoenleinii was eradicated in most of the world with the introduction of griseofulvin in 1958.⁷ Terbinafine and itraconazole are currently the drugs of choice for therapy.¹⁰

Tinea capitis is the most common fungal infection in children, with 1 in 20 US children displaying evidence of overt infection.¹¹ Infection in adults is rare and most affected patients typically display serious illnesses with concomitant immune compromise.¹² Only 3% to 5% of cases arise in patients older than 20 years.¹³ Adult hair appears to be relatively resistant to dermatophyte infection, probably from the fungistatic properties of long-chain fatty acids found in sebum.¹³ Tinea capitis in adults usually occurs in postmenopausal women, presumably from involution of sebaceous glands associated with declining estrogen levels. Patients typically exhibit erythematous scaly patches with central clearing, alopecia, varying degrees of inflammation, and few pustules, though exudative and heavily inflammatory lesions also have been described.¹⁴

In the current case, TC was not raised in the differential diagnosis. Regardless, given that scaly red patches and papules of the scalp may represent a dermatophyte infection in this patient population, clinicians are encouraged to consider this possibility. Transmission is by direct human-to-human contact and contact with objects containing fomites including brushes, combs, bedding, clothing, toys, furniture, and telephones.¹⁵ It is frequently spread among family members and classmates.¹⁶

Prior to World War II, most cases of TC in the United States were due to M canis, with Microsporum audouinii becoming more prevalent until the 1960s and 1970s when Trichophyton tonsurans began surging in incidence.^12,17 Currently, the latter organism is responsible for more than 95% of TC cases in the United States.¹⁸Microsporum canis is the main causative species in Europe but varies widely by country. In the Middle East and Africa, T violaceum is responsible for many infections.

Trichophyton rubrum–associated TC appears to be a rare occurrence. A global study in 1995 noted that less than 1% of TC cases were due to T rubrum infection, most having been described in emerging nations.¹² A meta-analysis of 9 studies from developed countries found only 9 of 10,145 cases of TC with a culture positive for T rubrum.¹⁴ In adults, infected patients typically exhibit either evidence of a concomitant fungal infection of the skin and/or nails or health conditions with impaired immunity, whereas in children, interfamilial spread appears more common.¹¹

VIENNA – A once-weekly oral antifungal drug known as VT-1161 will move into phase III clinical testing in 2017 based on its impressive performance in an interim analysis of a phase IIb study, Amir Tavakkol, PhD, reported at the annual congress of the European Academy of Dermatology and Venereology.

“We saw robust evidence of clinical and mycologic efficacy in patients with moderate to severe onychomycosis. This was true even in patients with nails considered very difficult to treat because of dermatophytomas and spikes, which are usually poor prognostic elements,” said Dr. Tavakkol, chief development officer at Viamet Pharmaceuticals in Durham, N.C., which is developing VT-1161.

Bruce Jancin/Frontline Medical News

[email protected]
 

VIENNA – A once-weekly oral antifungal drug known as VT-1161 will move into phase III clinical testing in 2017 based on its impressive performance in an interim analysis of a phase IIb study, Amir Tavakkol, PhD, reported at the annual congress of the European Academy of Dermatology and Venereology.

“We saw robust evidence of clinical and mycologic efficacy in patients with moderate to severe onychomycosis. This was true even in patients with nails considered very difficult to treat because of dermatophytomas and spikes, which are usually poor prognostic elements,” said Dr. Tavakkol, chief development officer at Viamet Pharmaceuticals in Durham, N.C., which is developing VT-1161.

Bruce Jancin/Frontline Medical News

[email protected]
 

VIENNA – A once-weekly oral antifungal drug known as VT-1161 will move into phase III clinical testing in 2017 based on its impressive performance in an interim analysis of a phase IIb study, Amir Tavakkol, PhD, reported at the annual congress of the European Academy of Dermatology and Venereology.

“We saw robust evidence of clinical and mycologic efficacy in patients with moderate to severe onychomycosis. This was true even in patients with nails considered very difficult to treat because of dermatophytomas and spikes, which are usually poor prognostic elements,” said Dr. Tavakkol, chief development officer at Viamet Pharmaceuticals in Durham, N.C., which is developing VT-1161.

Bruce Jancin/Frontline Medical News

[email protected]
 

Fungal skin infections may be missed or misdiagnosed by many dermatologists, according to the results of a survey published online in the Journal of the American Academy of Dermatology.

For the interactive survey, conducted during a session on fungal infections at the 2016 Orlando Dermatology Aesthetic and Clinical Conference, board-certified dermatologists viewed 13 clinical images (which included other conditions such as secondary syphilis and pityriasis rosea) and were asked via an audience response system whether or not they thought the case was a fungal skin infection. In only 1 of the 13 cases presented did 90% of the dermatologists correctly categorize the case as either a dermatomycosis or not, reported Ramsin Joseph Yadgar of George Washington University in Washington, D.C., and colleagues.

Although most cases (8 of 13) “were appropriately categorized by more than 50% of the audience, this percentage decreased as accuracy of categorization increased,” they wrote. “For example, in only 4 of the 13 cases did audience members accurately categorize the cases with more than 75% accuracy,” they said (J Am Acad Dermatol. 2016 Nov 11. pii: S0190-9622[16]30883-0. doi: 10.1016/j.jaad.2016.09.041).

Fungal skin infections may be missed or misdiagnosed by many dermatologists, according to the results of a survey published online in the Journal of the American Academy of Dermatology.

For the interactive survey, conducted during a session on fungal infections at the 2016 Orlando Dermatology Aesthetic and Clinical Conference, board-certified dermatologists viewed 13 clinical images (which included other conditions such as secondary syphilis and pityriasis rosea) and were asked via an audience response system whether or not they thought the case was a fungal skin infection. In only 1 of the 13 cases presented did 90% of the dermatologists correctly categorize the case as either a dermatomycosis or not, reported Ramsin Joseph Yadgar of George Washington University in Washington, D.C., and colleagues.

Although most cases (8 of 13) “were appropriately categorized by more than 50% of the audience, this percentage decreased as accuracy of categorization increased,” they wrote. “For example, in only 4 of the 13 cases did audience members accurately categorize the cases with more than 75% accuracy,” they said (J Am Acad Dermatol. 2016 Nov 11. pii: S0190-9622[16]30883-0. doi: 10.1016/j.jaad.2016.09.041).

Fungal skin infections may be missed or misdiagnosed by many dermatologists, according to the results of a survey published online in the Journal of the American Academy of Dermatology.

For the interactive survey, conducted during a session on fungal infections at the 2016 Orlando Dermatology Aesthetic and Clinical Conference, board-certified dermatologists viewed 13 clinical images (which included other conditions such as secondary syphilis and pityriasis rosea) and were asked via an audience response system whether or not they thought the case was a fungal skin infection. In only 1 of the 13 cases presented did 90% of the dermatologists correctly categorize the case as either a dermatomycosis or not, reported Ramsin Joseph Yadgar of George Washington University in Washington, D.C., and colleagues.

Although most cases (8 of 13) “were appropriately categorized by more than 50% of the audience, this percentage decreased as accuracy of categorization increased,” they wrote. “For example, in only 4 of the 13 cases did audience members accurately categorize the cases with more than 75% accuracy,” they said (J Am Acad Dermatol. 2016 Nov 11. pii: S0190-9622[16]30883-0. doi: 10.1016/j.jaad.2016.09.041).

LAS VEGAS – New topical treatment options for onychomycosis represent significant improvements over older agents, and may approach the success seen with oral drugs, according to Dr. Theodore Rosen, professor of dermatology, Baylor College of Medicine, Houston.

Efinaconazole and tavaborole both permeate the nail and allow for spreading to the lateral nail folds and hyponychium, Dr. Rosen said in a video interview at the Skin Disease Education Foundation’s annual Las Vegas Dermatology Seminar. Moreover, the topical treatments are popular with patients. Even if patients are not 100% clear, they are usually happy if their condition improves enough to wear sandals with confidence, Dr. Rosen added in the interview.

SDEF and this news organization are owned by the same parent company.

Dr. Rosen disclosed being a paid participant on the scientific advisory boards for Anacor and Valeant.

[email protected]

LAS VEGAS – New topical treatment options for onychomycosis represent significant improvements over older agents, and may approach the success seen with oral drugs, according to Dr. Theodore Rosen, professor of dermatology, Baylor College of Medicine, Houston.

Efinaconazole and tavaborole both permeate the nail and allow for spreading to the lateral nail folds and hyponychium, Dr. Rosen said in a video interview at the Skin Disease Education Foundation’s annual Las Vegas Dermatology Seminar. Moreover, the topical treatments are popular with patients. Even if patients are not 100% clear, they are usually happy if their condition improves enough to wear sandals with confidence, Dr. Rosen added in the interview.

SDEF and this news organization are owned by the same parent company.

Dr. Rosen disclosed being a paid participant on the scientific advisory boards for Anacor and Valeant.

[email protected]

LAS VEGAS – New topical treatment options for onychomycosis represent significant improvements over older agents, and may approach the success seen with oral drugs, according to Dr. Theodore Rosen, professor of dermatology, Baylor College of Medicine, Houston.

Efinaconazole and tavaborole both permeate the nail and allow for spreading to the lateral nail folds and hyponychium, Dr. Rosen said in a video interview at the Skin Disease Education Foundation’s annual Las Vegas Dermatology Seminar. Moreover, the topical treatments are popular with patients. Even if patients are not 100% clear, they are usually happy if their condition improves enough to wear sandals with confidence, Dr. Rosen added in the interview.

SDEF and this news organization are owned by the same parent company.

Dr. Rosen disclosed being a paid participant on the scientific advisory boards for Anacor and Valeant.

[email protected]

To the Editor:

Prior studies have assessed the quality of text-based dermatology information on the Internet using traditional search engine queries.¹ However, little is understood about the sources, accuracy, and quality of online dermatology images derived from direct image searches. Previous work has shown that direct search engine image queries were largely accurate for 3 pediatric dermatology diagnosis searches: atopic dermatitis, lichen striatus, and subcutaneous fat necrosis.² We assessed images obtained for common dermatologic conditions from a Google image search (GIS) compared to a traditional text-based Google web search (GWS).

Image results for 32 unique dermatologic search terms were analyzed (Table 1). These search terms were selected using the results of a prior study that identified the most common dermatologic diagnoses that led users to the 2 most popular dermatology-specific websites worldwide: the American Academy of Dermatology (www.aad.org) and DermNet New Zealand (www.dermnetnz.org).³ The Alexa directory (www.alexa.com), a large publicly available Internet analytics resource, was used to determine the most common dermatology search terms that led a user to either www.dermnetnz.org or www.aad.org. In addition, searches for the 3 most common types of skin cancer—melanoma, squamous cell carcinoma, and basal cell carcinoma—were included. Each term was entered into a GIS and a GWS. The first 10 results, which represent 92% of the websites ultimately visited by users,⁴ were analyzed. The source, diagnostic accuracy, and Fitzpatrick skin type of the images was determined. Website sources were organized into 11 categories. All data collection occurred within a 1-week period in August 2015.

A total of 320 images were analyzed. In the GIS, private websites (36%), dermatology association websites (28%), and general health information websites (10%) were the 3 most common sources. In the GWS, health information websites (35%), private websites (21%), and dermatology association websites (20%) accounted for the most common sources (Table 2). The majority of images were of Fitzpatrick skin types I and II (89%) and nearly all images were diagnostically accurate (98%). There was no statistically significant difference in accuracy of diagnosis between physician-associated websites (100% accuracy) versus nonphysician-associated sites (98% accuracy, P=.25).

Our results showed high diagnostic accuracy among the top GIS results for common dermatology search terms. Diagnostic accuracy did not vary between websites that were physician associated versus those that were not. Our results are comparable to the reported accuracy of online dermatologic health information.¹ In GIS results, the majority of images were provided by private websites, whereas the top websites in GWS results were health information websites.

Only 1% of images were of Fitzpatrick skin types VI and VII. Presentation of skin diseases is remarkably different based on the patient’s skin type.⁵ The shortage of readily accessible images of skin of color is in line with the lack of familiarity physicians and trainees have with dermatologic conditions in ethnic skin.⁶

Based on the results from this analysis, providers and patients searching for dermatologic conditions via a direct GIS should be cognizant of several considerations. Although our results showed that GIS was accurate, the searcher should note that image-based searches are not accompanied by relevant text that can help confirm relevancy and accuracy. Image searches depend on textual tags added by the source website. Websites that represent dermatological associations and academic centers can add an additional layer of confidence for users. Patients and clinicians also should be aware that the consideration of a patient’s Fitzpatrick skin type is critical when assessing the relevancy of a GIS result. In conclusion, search results via GIS queries are accurate for the dermatological diagnoses tested but may be lacking in skin of color variations, suggesting a potential unmet need based on our growing ethnic skin population.

To the Editor:

Prior studies have assessed the quality of text-based dermatology information on the Internet using traditional search engine queries.¹ However, little is understood about the sources, accuracy, and quality of online dermatology images derived from direct image searches. Previous work has shown that direct search engine image queries were largely accurate for 3 pediatric dermatology diagnosis searches: atopic dermatitis, lichen striatus, and subcutaneous fat necrosis.² We assessed images obtained for common dermatologic conditions from a Google image search (GIS) compared to a traditional text-based Google web search (GWS).

Image results for 32 unique dermatologic search terms were analyzed (Table 1). These search terms were selected using the results of a prior study that identified the most common dermatologic diagnoses that led users to the 2 most popular dermatology-specific websites worldwide: the American Academy of Dermatology (www.aad.org) and DermNet New Zealand (www.dermnetnz.org).³ The Alexa directory (www.alexa.com), a large publicly available Internet analytics resource, was used to determine the most common dermatology search terms that led a user to either www.dermnetnz.org or www.aad.org. In addition, searches for the 3 most common types of skin cancer—melanoma, squamous cell carcinoma, and basal cell carcinoma—were included. Each term was entered into a GIS and a GWS. The first 10 results, which represent 92% of the websites ultimately visited by users,⁴ were analyzed. The source, diagnostic accuracy, and Fitzpatrick skin type of the images was determined. Website sources were organized into 11 categories. All data collection occurred within a 1-week period in August 2015.

A total of 320 images were analyzed. In the GIS, private websites (36%), dermatology association websites (28%), and general health information websites (10%) were the 3 most common sources. In the GWS, health information websites (35%), private websites (21%), and dermatology association websites (20%) accounted for the most common sources (Table 2). The majority of images were of Fitzpatrick skin types I and II (89%) and nearly all images were diagnostically accurate (98%). There was no statistically significant difference in accuracy of diagnosis between physician-associated websites (100% accuracy) versus nonphysician-associated sites (98% accuracy, P=.25).

Our results showed high diagnostic accuracy among the top GIS results for common dermatology search terms. Diagnostic accuracy did not vary between websites that were physician associated versus those that were not. Our results are comparable to the reported accuracy of online dermatologic health information.¹ In GIS results, the majority of images were provided by private websites, whereas the top websites in GWS results were health information websites.

Only 1% of images were of Fitzpatrick skin types VI and VII. Presentation of skin diseases is remarkably different based on the patient’s skin type.⁵ The shortage of readily accessible images of skin of color is in line with the lack of familiarity physicians and trainees have with dermatologic conditions in ethnic skin.⁶

Based on the results from this analysis, providers and patients searching for dermatologic conditions via a direct GIS should be cognizant of several considerations. Although our results showed that GIS was accurate, the searcher should note that image-based searches are not accompanied by relevant text that can help confirm relevancy and accuracy. Image searches depend on textual tags added by the source website. Websites that represent dermatological associations and academic centers can add an additional layer of confidence for users. Patients and clinicians also should be aware that the consideration of a patient’s Fitzpatrick skin type is critical when assessing the relevancy of a GIS result. In conclusion, search results via GIS queries are accurate for the dermatological diagnoses tested but may be lacking in skin of color variations, suggesting a potential unmet need based on our growing ethnic skin population.

To the Editor:

Prior studies have assessed the quality of text-based dermatology information on the Internet using traditional search engine queries.¹ However, little is understood about the sources, accuracy, and quality of online dermatology images derived from direct image searches. Previous work has shown that direct search engine image queries were largely accurate for 3 pediatric dermatology diagnosis searches: atopic dermatitis, lichen striatus, and subcutaneous fat necrosis.² We assessed images obtained for common dermatologic conditions from a Google image search (GIS) compared to a traditional text-based Google web search (GWS).

Image results for 32 unique dermatologic search terms were analyzed (Table 1). These search terms were selected using the results of a prior study that identified the most common dermatologic diagnoses that led users to the 2 most popular dermatology-specific websites worldwide: the American Academy of Dermatology (www.aad.org) and DermNet New Zealand (www.dermnetnz.org).³ The Alexa directory (www.alexa.com), a large publicly available Internet analytics resource, was used to determine the most common dermatology search terms that led a user to either www.dermnetnz.org or www.aad.org. In addition, searches for the 3 most common types of skin cancer—melanoma, squamous cell carcinoma, and basal cell carcinoma—were included. Each term was entered into a GIS and a GWS. The first 10 results, which represent 92% of the websites ultimately visited by users,⁴ were analyzed. The source, diagnostic accuracy, and Fitzpatrick skin type of the images was determined. Website sources were organized into 11 categories. All data collection occurred within a 1-week period in August 2015.

A total of 320 images were analyzed. In the GIS, private websites (36%), dermatology association websites (28%), and general health information websites (10%) were the 3 most common sources. In the GWS, health information websites (35%), private websites (21%), and dermatology association websites (20%) accounted for the most common sources (Table 2). The majority of images were of Fitzpatrick skin types I and II (89%) and nearly all images were diagnostically accurate (98%). There was no statistically significant difference in accuracy of diagnosis between physician-associated websites (100% accuracy) versus nonphysician-associated sites (98% accuracy, P=.25).

Our results showed high diagnostic accuracy among the top GIS results for common dermatology search terms. Diagnostic accuracy did not vary between websites that were physician associated versus those that were not. Our results are comparable to the reported accuracy of online dermatologic health information.¹ In GIS results, the majority of images were provided by private websites, whereas the top websites in GWS results were health information websites.

Only 1% of images were of Fitzpatrick skin types VI and VII. Presentation of skin diseases is remarkably different based on the patient’s skin type.⁵ The shortage of readily accessible images of skin of color is in line with the lack of familiarity physicians and trainees have with dermatologic conditions in ethnic skin.⁶

Based on the results from this analysis, providers and patients searching for dermatologic conditions via a direct GIS should be cognizant of several considerations. Although our results showed that GIS was accurate, the searcher should note that image-based searches are not accompanied by relevant text that can help confirm relevancy and accuracy. Image searches depend on textual tags added by the source website. Websites that represent dermatological associations and academic centers can add an additional layer of confidence for users. Patients and clinicians also should be aware that the consideration of a patient’s Fitzpatrick skin type is critical when assessing the relevancy of a GIS result. In conclusion, search results via GIS queries are accurate for the dermatological diagnoses tested but may be lacking in skin of color variations, suggesting a potential unmet need based on our growing ethnic skin population.