DermaDiagnosis

ANSWER
The answer is temporal triangular alopecia (choice “d”), an unusual form of permanent hair loss preferentially affecting the exact area depicted in this case.

Alopecia areata (choice “a”) involves localized hair loss. By contrast, this patient never had hair in this area to lose.

Nevus sebaceous (choice “b”) is a congenital hamartoma that is typically hairless; there are no follicles, and the bumpy, rough surface is composed of sebaceous globules.

Cutis aplasia (choice “c”) manifests with hairless lesions, but there is marked aplasia of the skin as well and no surface adnexae, let alone hairs or follicles.

DISCUSSION
Temporal triangular alopecia (TTA) is an unusual type of alopecia. Of unknown origin, it usually affects this area of the scalp—and usually unilaterally. Approximately one-third of TTA patients are born with the condition; the rest develop it in the first two to three years of life. As in this case, it is often wrongly attributed to the use of forceps but has nothing to do with trauma. One school of thought holds that TTA is probably an inherited condition—but others disagree.

TTA was originally known as congenital triangular alopecia. However, when enough cases had been accumulated to accurately determine the nature of the condition, it was realized that TTA is not always congenital or triangular. Thus, a new name was bestowed.

The hallmark of TTA is the normal number of hair follicles that only grow vellus hairs. The solitary peripheral tuft of terminal dark hairs is typical of TTA and thus a confirmatory finding.

TREATMENT/PROGNOSIS
TTA is by definition permanent. Since there’s no inflammation (a key difference from alopecia areata), steroids are useless. The only successful treatment for TTA, if any is attempted, is hair transplantation. As of this writing, the family is mulling this treatment option.

ANSWER
The answer is temporal triangular alopecia (choice “d”), an unusual form of permanent hair loss preferentially affecting the exact area depicted in this case.

Alopecia areata (choice “a”) involves localized hair loss. By contrast, this patient never had hair in this area to lose.

Nevus sebaceous (choice “b”) is a congenital hamartoma that is typically hairless; there are no follicles, and the bumpy, rough surface is composed of sebaceous globules.

Cutis aplasia (choice “c”) manifests with hairless lesions, but there is marked aplasia of the skin as well and no surface adnexae, let alone hairs or follicles.

DISCUSSION
Temporal triangular alopecia (TTA) is an unusual type of alopecia. Of unknown origin, it usually affects this area of the scalp—and usually unilaterally. Approximately one-third of TTA patients are born with the condition; the rest develop it in the first two to three years of life. As in this case, it is often wrongly attributed to the use of forceps but has nothing to do with trauma. One school of thought holds that TTA is probably an inherited condition—but others disagree.

TTA was originally known as congenital triangular alopecia. However, when enough cases had been accumulated to accurately determine the nature of the condition, it was realized that TTA is not always congenital or triangular. Thus, a new name was bestowed.

The hallmark of TTA is the normal number of hair follicles that only grow vellus hairs. The solitary peripheral tuft of terminal dark hairs is typical of TTA and thus a confirmatory finding.

TREATMENT/PROGNOSIS
TTA is by definition permanent. Since there’s no inflammation (a key difference from alopecia areata), steroids are useless. The only successful treatment for TTA, if any is attempted, is hair transplantation. As of this writing, the family is mulling this treatment option.

ANSWER
The answer is temporal triangular alopecia (choice “d”), an unusual form of permanent hair loss preferentially affecting the exact area depicted in this case.

Alopecia areata (choice “a”) involves localized hair loss. By contrast, this patient never had hair in this area to lose.

Nevus sebaceous (choice “b”) is a congenital hamartoma that is typically hairless; there are no follicles, and the bumpy, rough surface is composed of sebaceous globules.

Cutis aplasia (choice “c”) manifests with hairless lesions, but there is marked aplasia of the skin as well and no surface adnexae, let alone hairs or follicles.

DISCUSSION
Temporal triangular alopecia (TTA) is an unusual type of alopecia. Of unknown origin, it usually affects this area of the scalp—and usually unilaterally. Approximately one-third of TTA patients are born with the condition; the rest develop it in the first two to three years of life. As in this case, it is often wrongly attributed to the use of forceps but has nothing to do with trauma. One school of thought holds that TTA is probably an inherited condition—but others disagree.

TTA was originally known as congenital triangular alopecia. However, when enough cases had been accumulated to accurately determine the nature of the condition, it was realized that TTA is not always congenital or triangular. Thus, a new name was bestowed.

The hallmark of TTA is the normal number of hair follicles that only grow vellus hairs. The solitary peripheral tuft of terminal dark hairs is typical of TTA and thus a confirmatory finding.

TREATMENT/PROGNOSIS
TTA is by definition permanent. Since there’s no inflammation (a key difference from alopecia areata), steroids are useless. The only successful treatment for TTA, if any is attempted, is hair transplantation. As of this writing, the family is mulling this treatment option.

ANSWER
The correct answer is lichen nitidus (choice “b”), a harmless, self-limited condition of unknown origin. The lesions’ flat-topped (planar) surfaces and tendency to form in linear configurations along lines of trauma (so-called Koebner phenomenon) are also features seen in lichen planus (choice “d”) lesions; however, the latter are almost always pruritic and purple in color. Ironically, the histologic pattern seen in both is almost identical.

An extremely common condition, molluscum contagiosum (choice “a”) presents with multiple tiny papules. But these are not planar, and most will have an umbilicated center. See the Discussion for ways to distinguish it from lichen nitidus.

Flat warts (choice “c”), known as verruca plana, can strongly resemble lichen nitidus, but they are not as flat-topped and do not appear white. They do Koebnerize, however, which occasionally makes the distinction difficult.

DISCUSSION
Lichen nitidus (LN) is an unusual but benign condition primarily affecting children and young adults. Due to the contrast, the white planar papules are easier to see on darker skin. As is the case with many dermatologic diagnoses, LN is easily identified if you’ve heard of it and therefore know what to expect—but much more difficult if you haven’t.

LN’s unique manifestation distinguishes it from other items in the differential. For example, molluscum and LN can easily be confused, especially since both primarily affect children. But the pathognomic central umbilication of molluscum lesions is the key distinguishing feature; the best way to highlight it is with a short blast of liquid nitrogen. (Usually, though, the planar surfaces of LN are sufficient to distinguish it from other conditions.)

In the United States, the term Koebner phenomenon refers to the tendency for lesions to form along areas of trauma, usually in a linear configuration. All four items in our differential can present in this way. However, the term auto-inoculation might be more properly applied to conditions such as warts and molluscum, since the trauma has merely inoculated the organism into the skin. Inflammatory conditions such as LN and lichen planus are not truly “spread” by the trauma.

Linearly configured lesions are sufficiently unusual in dermatology to warrant their own differential. Among those that can present in this manner are psoriasis, lichen sclerosus et atrophicus, and vitiligo.

TREATMENT/PROGNOSIS
Our LN patient did not require any treatment, nor was any possible. The condition is quite likely to clear on its own, leaving little if any evidence in its wake.

I often show affected patients and/or their parents pictures of these types of conditions from our textbooks, for added reassurance. And in this day and age, I direct them to websites where they can do more investigation on their own time.

The effective practice of dermatology (and of all medicine, for that matter) includes more than merely making a correct diagnosis: I believe we’re obliged to “sell” it as well.

ANSWER
The correct answer is lichen nitidus (choice “b”), a harmless, self-limited condition of unknown origin. The lesions’ flat-topped (planar) surfaces and tendency to form in linear configurations along lines of trauma (so-called Koebner phenomenon) are also features seen in lichen planus (choice “d”) lesions; however, the latter are almost always pruritic and purple in color. Ironically, the histologic pattern seen in both is almost identical.

An extremely common condition, molluscum contagiosum (choice “a”) presents with multiple tiny papules. But these are not planar, and most will have an umbilicated center. See the Discussion for ways to distinguish it from lichen nitidus.

Flat warts (choice “c”), known as verruca plana, can strongly resemble lichen nitidus, but they are not as flat-topped and do not appear white. They do Koebnerize, however, which occasionally makes the distinction difficult.

DISCUSSION
Lichen nitidus (LN) is an unusual but benign condition primarily affecting children and young adults. Due to the contrast, the white planar papules are easier to see on darker skin. As is the case with many dermatologic diagnoses, LN is easily identified if you’ve heard of it and therefore know what to expect—but much more difficult if you haven’t.

LN’s unique manifestation distinguishes it from other items in the differential. For example, molluscum and LN can easily be confused, especially since both primarily affect children. But the pathognomic central umbilication of molluscum lesions is the key distinguishing feature; the best way to highlight it is with a short blast of liquid nitrogen. (Usually, though, the planar surfaces of LN are sufficient to distinguish it from other conditions.)

In the United States, the term Koebner phenomenon refers to the tendency for lesions to form along areas of trauma, usually in a linear configuration. All four items in our differential can present in this way. However, the term auto-inoculation might be more properly applied to conditions such as warts and molluscum, since the trauma has merely inoculated the organism into the skin. Inflammatory conditions such as LN and lichen planus are not truly “spread” by the trauma.

Linearly configured lesions are sufficiently unusual in dermatology to warrant their own differential. Among those that can present in this manner are psoriasis, lichen sclerosus et atrophicus, and vitiligo.

TREATMENT/PROGNOSIS
Our LN patient did not require any treatment, nor was any possible. The condition is quite likely to clear on its own, leaving little if any evidence in its wake.

I often show affected patients and/or their parents pictures of these types of conditions from our textbooks, for added reassurance. And in this day and age, I direct them to websites where they can do more investigation on their own time.

The effective practice of dermatology (and of all medicine, for that matter) includes more than merely making a correct diagnosis: I believe we’re obliged to “sell” it as well.

ANSWER
The correct answer is lichen nitidus (choice “b”), a harmless, self-limited condition of unknown origin. The lesions’ flat-topped (planar) surfaces and tendency to form in linear configurations along lines of trauma (so-called Koebner phenomenon) are also features seen in lichen planus (choice “d”) lesions; however, the latter are almost always pruritic and purple in color. Ironically, the histologic pattern seen in both is almost identical.

An extremely common condition, molluscum contagiosum (choice “a”) presents with multiple tiny papules. But these are not planar, and most will have an umbilicated center. See the Discussion for ways to distinguish it from lichen nitidus.

Flat warts (choice “c”), known as verruca plana, can strongly resemble lichen nitidus, but they are not as flat-topped and do not appear white. They do Koebnerize, however, which occasionally makes the distinction difficult.

DISCUSSION
Lichen nitidus (LN) is an unusual but benign condition primarily affecting children and young adults. Due to the contrast, the white planar papules are easier to see on darker skin. As is the case with many dermatologic diagnoses, LN is easily identified if you’ve heard of it and therefore know what to expect—but much more difficult if you haven’t.

LN’s unique manifestation distinguishes it from other items in the differential. For example, molluscum and LN can easily be confused, especially since both primarily affect children. But the pathognomic central umbilication of molluscum lesions is the key distinguishing feature; the best way to highlight it is with a short blast of liquid nitrogen. (Usually, though, the planar surfaces of LN are sufficient to distinguish it from other conditions.)

In the United States, the term Koebner phenomenon refers to the tendency for lesions to form along areas of trauma, usually in a linear configuration. All four items in our differential can present in this way. However, the term auto-inoculation might be more properly applied to conditions such as warts and molluscum, since the trauma has merely inoculated the organism into the skin. Inflammatory conditions such as LN and lichen planus are not truly “spread” by the trauma.

Linearly configured lesions are sufficiently unusual in dermatology to warrant their own differential. Among those that can present in this manner are psoriasis, lichen sclerosus et atrophicus, and vitiligo.

TREATMENT/PROGNOSIS
Our LN patient did not require any treatment, nor was any possible. The condition is quite likely to clear on its own, leaving little if any evidence in its wake.

I often show affected patients and/or their parents pictures of these types of conditions from our textbooks, for added reassurance. And in this day and age, I direct them to websites where they can do more investigation on their own time.

The effective practice of dermatology (and of all medicine, for that matter) includes more than merely making a correct diagnosis: I believe we’re obliged to “sell” it as well.

ANSWER
The correct answer is soft corn (choice “c”). They are caused by bony friction and almost always found between the fourth and fifth toes.

Soft corns are often mistaken for warts (choice “a”). But warts don’t present as painful, macerated lesions between the toes.

Morton neuroma (choice “b”) is actually a neurofibroma, not a virtual tumor. It is usually found on the plantar forefoot between the second and third toes.

Interdigital fungal infections (choice “d”) often develop between the fourth and fifth toes and are often macerated. However, they do not take the form of lesions and do not hurt.

DISCUSSION
Soft corns are known in podiatric circles as heloma molle but are sometimes called kissing corns because they’re caused by friction between bony prominences on the fourth and fifth phalanges, which rub together with every step. Normally, these toes are hourglass shaped, but in patients prone to develop soft corns, the proximal bases of the toes are too wide. The type of shoe the patient wears can be an important factor as well, especially when high heels and/or narrow toe boxes are involved.

The treatment of soft corns can be nonsurgical—sometimes as simple as separating the toes with a tuft of lambswool. However, surgical intervention is often required. In such cases, the head of the proximal phalanx is cut and removed to make the adjacent bones more parallel. Occasionally, the skin is so damaged that it too must be removed and the toes sewn together.

Removing corns with chemicals, shaving, or excision provides no lasting relief, since these  methods do not address the underlying structural issues.

Hard corns, also known as heloma durum, tend to develop on the dorsal aspect of the fifth toe secondary to pressure from shoes. Changing the type of shoe worn is one solution, but often, as with soft corns, the underlying bony prominence must be addressed.

There is a third type of corn, the periungual corn, which develops on or near the edge of a nail. These corns are often erroneously called warts.

This patient was referred to a podiatrist, who will likely solve the problem. There is no topical product that can help, and nonsurgical approaches will provide temporary relief at best.

ANSWER
The correct answer is soft corn (choice “c”). They are caused by bony friction and almost always found between the fourth and fifth toes.

Soft corns are often mistaken for warts (choice “a”). But warts don’t present as painful, macerated lesions between the toes.

Morton neuroma (choice “b”) is actually a neurofibroma, not a virtual tumor. It is usually found on the plantar forefoot between the second and third toes.

Interdigital fungal infections (choice “d”) often develop between the fourth and fifth toes and are often macerated. However, they do not take the form of lesions and do not hurt.

DISCUSSION
Soft corns are known in podiatric circles as heloma molle but are sometimes called kissing corns because they’re caused by friction between bony prominences on the fourth and fifth phalanges, which rub together with every step. Normally, these toes are hourglass shaped, but in patients prone to develop soft corns, the proximal bases of the toes are too wide. The type of shoe the patient wears can be an important factor as well, especially when high heels and/or narrow toe boxes are involved.

The treatment of soft corns can be nonsurgical—sometimes as simple as separating the toes with a tuft of lambswool. However, surgical intervention is often required. In such cases, the head of the proximal phalanx is cut and removed to make the adjacent bones more parallel. Occasionally, the skin is so damaged that it too must be removed and the toes sewn together.

Removing corns with chemicals, shaving, or excision provides no lasting relief, since these  methods do not address the underlying structural issues.

Hard corns, also known as heloma durum, tend to develop on the dorsal aspect of the fifth toe secondary to pressure from shoes. Changing the type of shoe worn is one solution, but often, as with soft corns, the underlying bony prominence must be addressed.

There is a third type of corn, the periungual corn, which develops on or near the edge of a nail. These corns are often erroneously called warts.

This patient was referred to a podiatrist, who will likely solve the problem. There is no topical product that can help, and nonsurgical approaches will provide temporary relief at best.

ANSWER
The correct answer is soft corn (choice “c”). They are caused by bony friction and almost always found between the fourth and fifth toes.

Soft corns are often mistaken for warts (choice “a”). But warts don’t present as painful, macerated lesions between the toes.

Morton neuroma (choice “b”) is actually a neurofibroma, not a virtual tumor. It is usually found on the plantar forefoot between the second and third toes.

Interdigital fungal infections (choice “d”) often develop between the fourth and fifth toes and are often macerated. However, they do not take the form of lesions and do not hurt.

DISCUSSION
Soft corns are known in podiatric circles as heloma molle but are sometimes called kissing corns because they’re caused by friction between bony prominences on the fourth and fifth phalanges, which rub together with every step. Normally, these toes are hourglass shaped, but in patients prone to develop soft corns, the proximal bases of the toes are too wide. The type of shoe the patient wears can be an important factor as well, especially when high heels and/or narrow toe boxes are involved.

The treatment of soft corns can be nonsurgical—sometimes as simple as separating the toes with a tuft of lambswool. However, surgical intervention is often required. In such cases, the head of the proximal phalanx is cut and removed to make the adjacent bones more parallel. Occasionally, the skin is so damaged that it too must be removed and the toes sewn together.

Removing corns with chemicals, shaving, or excision provides no lasting relief, since these  methods do not address the underlying structural issues.

Hard corns, also known as heloma durum, tend to develop on the dorsal aspect of the fifth toe secondary to pressure from shoes. Changing the type of shoe worn is one solution, but often, as with soft corns, the underlying bony prominence must be addressed.

There is a third type of corn, the periungual corn, which develops on or near the edge of a nail. These corns are often erroneously called warts.

This patient was referred to a podiatrist, who will likely solve the problem. There is no topical product that can help, and nonsurgical approaches will provide temporary relief at best.

ANSWER
The correct answer is poikiloderma of Civatte (choice “c”), details of which are discussed below.

Poikiloderma vasculare atrophicans (choice “a”) can be an early indication of T-cell lymphoma but would probably not be chronic or confined to sun-exposed skin.

Several forms of lupus (choice “b”) can present with poikilodermatous skin changes, but these would probably not be chronic.

Dermatoheliosis (choice “d”) is the term for the collective effects of overexposure to the sun, of which poikiloderma of Civatte is but one example.

DISCUSSION
The French dermatologist Achille Civatte (1877-1956) first described this particular pattern of sun damage in 1923—about the same time that sunbathing became fashionable among the well-off in the post-WWI era. He noted the distinct combination of telangiectasias, hyperpigmentation, and epidermal atrophy affecting the bilateral neck and lower face, combined with sharply defined sparing of the portion of the anterior neck shaded by the chin. Poikiloderma of Civatte (PC) is extremely common, especially in middle-aged women and, as one might expect, in those with a history of excessive sun exposure over a period of many years.

Though sun-caused, PC is a purely cosmetic issue and does not lead to skin cancer. While it typically causes no symptoms, it does become more obvious with time. The changes are so gradual that others typically notice them before the patient becomes aware.

Transposing these types of skin changes to other locations would make them considerably more worrisome, specifically in the context of possible incipient T-cell lymphoma—one of the very few types of skin cancer that can take years to evolve into frank cancer. But the atrophy, telangiectasias, and discoloration signaling early cutaneous T-cell lymphoma are usually seen in non–sun-exposed skin, particularly in the waistline and groin.

Poikiloderma vasculare atrophicans is only one of several manifestations termed premycotic. This refers to mycosis fungoides, one of the two most common forms of T-cell lymphoma. Serial biopsy, sometimes over the span of several years, is often used to track such changes.

Pulsed light devices and certain types of lasers have been used successfully to treat PC. Our patient, however, declined treatment, declaring her firm intention to maintain “a healthy tan” year-round.

ANSWER
The correct answer is poikiloderma of Civatte (choice “c”), details of which are discussed below.

Poikiloderma vasculare atrophicans (choice “a”) can be an early indication of T-cell lymphoma but would probably not be chronic or confined to sun-exposed skin.

Several forms of lupus (choice “b”) can present with poikilodermatous skin changes, but these would probably not be chronic.

Dermatoheliosis (choice “d”) is the term for the collective effects of overexposure to the sun, of which poikiloderma of Civatte is but one example.

DISCUSSION
The French dermatologist Achille Civatte (1877-1956) first described this particular pattern of sun damage in 1923—about the same time that sunbathing became fashionable among the well-off in the post-WWI era. He noted the distinct combination of telangiectasias, hyperpigmentation, and epidermal atrophy affecting the bilateral neck and lower face, combined with sharply defined sparing of the portion of the anterior neck shaded by the chin. Poikiloderma of Civatte (PC) is extremely common, especially in middle-aged women and, as one might expect, in those with a history of excessive sun exposure over a period of many years.

Though sun-caused, PC is a purely cosmetic issue and does not lead to skin cancer. While it typically causes no symptoms, it does become more obvious with time. The changes are so gradual that others typically notice them before the patient becomes aware.

Transposing these types of skin changes to other locations would make them considerably more worrisome, specifically in the context of possible incipient T-cell lymphoma—one of the very few types of skin cancer that can take years to evolve into frank cancer. But the atrophy, telangiectasias, and discoloration signaling early cutaneous T-cell lymphoma are usually seen in non–sun-exposed skin, particularly in the waistline and groin.

Poikiloderma vasculare atrophicans is only one of several manifestations termed premycotic. This refers to mycosis fungoides, one of the two most common forms of T-cell lymphoma. Serial biopsy, sometimes over the span of several years, is often used to track such changes.

Pulsed light devices and certain types of lasers have been used successfully to treat PC. Our patient, however, declined treatment, declaring her firm intention to maintain “a healthy tan” year-round.

ANSWER
The correct answer is poikiloderma of Civatte (choice “c”), details of which are discussed below.

Poikiloderma vasculare atrophicans (choice “a”) can be an early indication of T-cell lymphoma but would probably not be chronic or confined to sun-exposed skin.

Several forms of lupus (choice “b”) can present with poikilodermatous skin changes, but these would probably not be chronic.

Dermatoheliosis (choice “d”) is the term for the collective effects of overexposure to the sun, of which poikiloderma of Civatte is but one example.

DISCUSSION
The French dermatologist Achille Civatte (1877-1956) first described this particular pattern of sun damage in 1923—about the same time that sunbathing became fashionable among the well-off in the post-WWI era. He noted the distinct combination of telangiectasias, hyperpigmentation, and epidermal atrophy affecting the bilateral neck and lower face, combined with sharply defined sparing of the portion of the anterior neck shaded by the chin. Poikiloderma of Civatte (PC) is extremely common, especially in middle-aged women and, as one might expect, in those with a history of excessive sun exposure over a period of many years.

Though sun-caused, PC is a purely cosmetic issue and does not lead to skin cancer. While it typically causes no symptoms, it does become more obvious with time. The changes are so gradual that others typically notice them before the patient becomes aware.

Transposing these types of skin changes to other locations would make them considerably more worrisome, specifically in the context of possible incipient T-cell lymphoma—one of the very few types of skin cancer that can take years to evolve into frank cancer. But the atrophy, telangiectasias, and discoloration signaling early cutaneous T-cell lymphoma are usually seen in non–sun-exposed skin, particularly in the waistline and groin.

Poikiloderma vasculare atrophicans is only one of several manifestations termed premycotic. This refers to mycosis fungoides, one of the two most common forms of T-cell lymphoma. Serial biopsy, sometimes over the span of several years, is often used to track such changes.

Pulsed light devices and certain types of lasers have been used successfully to treat PC. Our patient, however, declined treatment, declaring her firm intention to maintain “a healthy tan” year-round.

ANSWER

The correct answer is impetigo (choice “c”), a superficial infection usually caused by a combination of staph and strep organisms.

Psoriasis (choice “a”) would have presented with white, tenacious scaling and would not have been acute in onset.

Eczema (choice “b”) is definitely possible, but the patient’s rash has features not seen with this condition; see Discussion for details.

Fungal infection (choice “d”) is also definitely in the differential, but it is unlikely given the negative KOH, the lack of any source for such infection, and the complete lack of response to tolnaftate cream.

DISCUSSION

Impetigo has also been called impetiginized dermatitis because it almost always starts with minor breaks in the skin as a result of conditions such as eczema, acne, contact dermatitis, or insect bite. Thus provided with access to deeper portions of the epithelial surface, bacterial organisms that normally cause no problems on intact skin are able to create a minor but annoying condition we have come to call impetigo.

Mistakenly called infantigo in large parts of the United States, impetigo is quite common but nonetheless alarming. Rarely associated with morbidity, it tends to resolve in two to three weeks at most, even without treatment.

Impetigo has the reputation of being highly contagious; given enough heat and humidity, close living conditions, and lack of regular bathing and/or adequate treatment, it can spread rapidly. Those conditions existed commonly 100 years ago, when bathing was sporadic and often cursory, and multiple family members lived and slept in close quarters. In those days before the introduction of antibiotics, there were no good topical antimicrobial agents, either.

Another factor played a major role in impetigo, bolstering its fearsome reputation. The strains of strep (group A b-hemolytic strep) that caused most impetigo in those days included several so-called nephritogenic strains that could lead to a dreaded complication: acute poststreptococcal glomerulonephritis (APSGN). Also called Bright disease, it could and did lead to fatal renal failure—about which little could be done at the time.

Fortunately, such nephritogenic strains of strep are unusual now, with APSGN occurring at a rate of about 1:1,000,000 in developed countries. In those locations, most people live far different lives today, bathing and changing clothes daily and living in much less cramped quarters.

The patient’s atopy likely had an impact, for several reasons: Since staph colonization of atopic persons is quite common, it’s more likely that an infection will develop. Also, thinner skin that is easily broken, a plethora of complicating problems (eg, dry skin, eczema, contact dermatitis, and exaggerated reactions to insect bites), and a lower threshold for itching all make atopic persons more susceptible to infection.

Most likely, our patient had a touch of eczema or dry skin and scratched it. Then, as the condition progressed, she scratched it more. The peroxide she used would have been highly irritating, serving only to worsen matters.

From a diagnostic point of view, the honey-colored crust covering the lesion and the context in which it developed led to a provisional diagnosis of impetiginized dermatitis. She was treated with oral cephalexin (500 mg tid for 7 d), topical mupirocin (applied bid), and topical hydrocortisone cream 2.5% (daily application). At one week’s follow-up, the patient’s skin was almost totally clear. It’s very unlikely she’ll have any residual scarring or blemish.

Had the diagnosis been unclear, or had the patient not responded to treatment, other diagnoses would have been considered. Among them: discoid lupus, psoriasis, contact dermatitis, and Darier disease.

ANSWER

The correct answer is impetigo (choice “c”), a superficial infection usually caused by a combination of staph and strep organisms.

Psoriasis (choice “a”) would have presented with white, tenacious scaling and would not have been acute in onset.

Eczema (choice “b”) is definitely possible, but the patient’s rash has features not seen with this condition; see Discussion for details.

Fungal infection (choice “d”) is also definitely in the differential, but it is unlikely given the negative KOH, the lack of any source for such infection, and the complete lack of response to tolnaftate cream.

DISCUSSION

Impetigo has also been called impetiginized dermatitis because it almost always starts with minor breaks in the skin as a result of conditions such as eczema, acne, contact dermatitis, or insect bite. Thus provided with access to deeper portions of the epithelial surface, bacterial organisms that normally cause no problems on intact skin are able to create a minor but annoying condition we have come to call impetigo.

Mistakenly called infantigo in large parts of the United States, impetigo is quite common but nonetheless alarming. Rarely associated with morbidity, it tends to resolve in two to three weeks at most, even without treatment.

Impetigo has the reputation of being highly contagious; given enough heat and humidity, close living conditions, and lack of regular bathing and/or adequate treatment, it can spread rapidly. Those conditions existed commonly 100 years ago, when bathing was sporadic and often cursory, and multiple family members lived and slept in close quarters. In those days before the introduction of antibiotics, there were no good topical antimicrobial agents, either.

Another factor played a major role in impetigo, bolstering its fearsome reputation. The strains of strep (group A b-hemolytic strep) that caused most impetigo in those days included several so-called nephritogenic strains that could lead to a dreaded complication: acute poststreptococcal glomerulonephritis (APSGN). Also called Bright disease, it could and did lead to fatal renal failure—about which little could be done at the time.

Fortunately, such nephritogenic strains of strep are unusual now, with APSGN occurring at a rate of about 1:1,000,000 in developed countries. In those locations, most people live far different lives today, bathing and changing clothes daily and living in much less cramped quarters.

The patient’s atopy likely had an impact, for several reasons: Since staph colonization of atopic persons is quite common, it’s more likely that an infection will develop. Also, thinner skin that is easily broken, a plethora of complicating problems (eg, dry skin, eczema, contact dermatitis, and exaggerated reactions to insect bites), and a lower threshold for itching all make atopic persons more susceptible to infection.

Most likely, our patient had a touch of eczema or dry skin and scratched it. Then, as the condition progressed, she scratched it more. The peroxide she used would have been highly irritating, serving only to worsen matters.

From a diagnostic point of view, the honey-colored crust covering the lesion and the context in which it developed led to a provisional diagnosis of impetiginized dermatitis. She was treated with oral cephalexin (500 mg tid for 7 d), topical mupirocin (applied bid), and topical hydrocortisone cream 2.5% (daily application). At one week’s follow-up, the patient’s skin was almost totally clear. It’s very unlikely she’ll have any residual scarring or blemish.

Had the diagnosis been unclear, or had the patient not responded to treatment, other diagnoses would have been considered. Among them: discoid lupus, psoriasis, contact dermatitis, and Darier disease.

ANSWER

The correct answer is impetigo (choice “c”), a superficial infection usually caused by a combination of staph and strep organisms.

Psoriasis (choice “a”) would have presented with white, tenacious scaling and would not have been acute in onset.

Eczema (choice “b”) is definitely possible, but the patient’s rash has features not seen with this condition; see Discussion for details.

Fungal infection (choice “d”) is also definitely in the differential, but it is unlikely given the negative KOH, the lack of any source for such infection, and the complete lack of response to tolnaftate cream.

DISCUSSION

Impetigo has also been called impetiginized dermatitis because it almost always starts with minor breaks in the skin as a result of conditions such as eczema, acne, contact dermatitis, or insect bite. Thus provided with access to deeper portions of the epithelial surface, bacterial organisms that normally cause no problems on intact skin are able to create a minor but annoying condition we have come to call impetigo.

Mistakenly called infantigo in large parts of the United States, impetigo is quite common but nonetheless alarming. Rarely associated with morbidity, it tends to resolve in two to three weeks at most, even without treatment.

Impetigo has the reputation of being highly contagious; given enough heat and humidity, close living conditions, and lack of regular bathing and/or adequate treatment, it can spread rapidly. Those conditions existed commonly 100 years ago, when bathing was sporadic and often cursory, and multiple family members lived and slept in close quarters. In those days before the introduction of antibiotics, there were no good topical antimicrobial agents, either.

Another factor played a major role in impetigo, bolstering its fearsome reputation. The strains of strep (group A b-hemolytic strep) that caused most impetigo in those days included several so-called nephritogenic strains that could lead to a dreaded complication: acute poststreptococcal glomerulonephritis (APSGN). Also called Bright disease, it could and did lead to fatal renal failure—about which little could be done at the time.

Fortunately, such nephritogenic strains of strep are unusual now, with APSGN occurring at a rate of about 1:1,000,000 in developed countries. In those locations, most people live far different lives today, bathing and changing clothes daily and living in much less cramped quarters.

The patient’s atopy likely had an impact, for several reasons: Since staph colonization of atopic persons is quite common, it’s more likely that an infection will develop. Also, thinner skin that is easily broken, a plethora of complicating problems (eg, dry skin, eczema, contact dermatitis, and exaggerated reactions to insect bites), and a lower threshold for itching all make atopic persons more susceptible to infection.

Most likely, our patient had a touch of eczema or dry skin and scratched it. Then, as the condition progressed, she scratched it more. The peroxide she used would have been highly irritating, serving only to worsen matters.

From a diagnostic point of view, the honey-colored crust covering the lesion and the context in which it developed led to a provisional diagnosis of impetiginized dermatitis. She was treated with oral cephalexin (500 mg tid for 7 d), topical mupirocin (applied bid), and topical hydrocortisone cream 2.5% (daily application). At one week’s follow-up, the patient’s skin was almost totally clear. It’s very unlikely she’ll have any residual scarring or blemish.

Had the diagnosis been unclear, or had the patient not responded to treatment, other diagnoses would have been considered. Among them: discoid lupus, psoriasis, contact dermatitis, and Darier disease.

ANSWER

The correct answer is an allergic reaction to a contactant, most likely the triple-antibiotic ointment (choice “d”).

Irritant reactions to tape adhesive (choice “a”) are extremely common. However, the resultant rash would have been confined to the linear areas where the tape touched his skin.

Dissolving sutures, such as those used in this case, can provoke a “suture granuloma”—essentially a foreign body reaction to the suture material (choice “b”). But this would have caused a focal area of swelling and redness, and very possibly a show of pus.

Postop wound infections (choice “c”) are also quite common. However, they would not manifest solely with itching in a papulovesicular rash surrounding the wound. Had infection developed, the redness would have been broad-based, with ill-defined margins, and the patient’s complaint would have been of pain, not itching. No vesicles would have been seen with bacterial infection.

DISCUSSION

This case illustrates the phenomenon of “treatment as problem,” in which the medication the patient applies becomes more problematic than the condition being addressed. Reactions to the neomycin in triple-antibiotic ointment are common but still provoke considerable worry on the part of patients and providers alike, especially when mistaken for “infection.”

This patient, like many, was dubious of the diagnosis, pointing out that he had used this same topical medication on many occasions without incident (though not recently). What he didn’t know is that it takes repeated exposure to a given allergen to develop T-memory cells that eventually begin to react. This same phenomenon is seen with poison ivy; patients will recall the ability, as a child, to practically wallow in poison ivy with impunity, making them doubtful about being allergic to it as an adult.

Neomycin, an aminoglycoside with a fairly wide spectrum of antibacterial activity, was first noted as a contact allergen in 1952. It is such a notorious offender that it was named Allergen of the Year in 2010 by the American Contact Dermatology Society.

For the past 20 years, 7% to 13% of patch tests surveyed were positive for neomycin. For reasons not entirely clear, Americans older than 60 are 150% more likely to experience a reaction to neomycin than are younger patients. (It could simply be that they’ve had more chances for exposure.)

In another interesting twist, the ointment vehicle appears to play a role. A reaction to this preparation is considerably more likely than to the same drug in other forms (eg, powders, solutions, creams). This is true of most medications, such as topical steroids, which are effectively self-occluded by this vehicle.

Persons with impaired barrier function, such as those with atopic dermatitis or whose skin has been prepped for surgery, appear to be at increased risk for these types of contact dermatoses.

Though there are other items in the differential, the configuration of the papulovesicular rash and the sole symptom of itching are essentially pathognomic for contact dermatitis. Besides the use of potent topical steroids for a few days, the real “cure” for this problem is for the patient to switch to “double-antibiotic” creams or ointments that do not include neomycin. 

ANSWER

The correct answer is an allergic reaction to a contactant, most likely the triple-antibiotic ointment (choice “d”).

Irritant reactions to tape adhesive (choice “a”) are extremely common. However, the resultant rash would have been confined to the linear areas where the tape touched his skin.

Dissolving sutures, such as those used in this case, can provoke a “suture granuloma”—essentially a foreign body reaction to the suture material (choice “b”). But this would have caused a focal area of swelling and redness, and very possibly a show of pus.

Postop wound infections (choice “c”) are also quite common. However, they would not manifest solely with itching in a papulovesicular rash surrounding the wound. Had infection developed, the redness would have been broad-based, with ill-defined margins, and the patient’s complaint would have been of pain, not itching. No vesicles would have been seen with bacterial infection.

DISCUSSION

This case illustrates the phenomenon of “treatment as problem,” in which the medication the patient applies becomes more problematic than the condition being addressed. Reactions to the neomycin in triple-antibiotic ointment are common but still provoke considerable worry on the part of patients and providers alike, especially when mistaken for “infection.”

This patient, like many, was dubious of the diagnosis, pointing out that he had used this same topical medication on many occasions without incident (though not recently). What he didn’t know is that it takes repeated exposure to a given allergen to develop T-memory cells that eventually begin to react. This same phenomenon is seen with poison ivy; patients will recall the ability, as a child, to practically wallow in poison ivy with impunity, making them doubtful about being allergic to it as an adult.

Neomycin, an aminoglycoside with a fairly wide spectrum of antibacterial activity, was first noted as a contact allergen in 1952. It is such a notorious offender that it was named Allergen of the Year in 2010 by the American Contact Dermatology Society.

For the past 20 years, 7% to 13% of patch tests surveyed were positive for neomycin. For reasons not entirely clear, Americans older than 60 are 150% more likely to experience a reaction to neomycin than are younger patients. (It could simply be that they’ve had more chances for exposure.)

In another interesting twist, the ointment vehicle appears to play a role. A reaction to this preparation is considerably more likely than to the same drug in other forms (eg, powders, solutions, creams). This is true of most medications, such as topical steroids, which are effectively self-occluded by this vehicle.

Persons with impaired barrier function, such as those with atopic dermatitis or whose skin has been prepped for surgery, appear to be at increased risk for these types of contact dermatoses.

Though there are other items in the differential, the configuration of the papulovesicular rash and the sole symptom of itching are essentially pathognomic for contact dermatitis. Besides the use of potent topical steroids for a few days, the real “cure” for this problem is for the patient to switch to “double-antibiotic” creams or ointments that do not include neomycin. 

ANSWER

The correct answer is an allergic reaction to a contactant, most likely the triple-antibiotic ointment (choice “d”).

Irritant reactions to tape adhesive (choice “a”) are extremely common. However, the resultant rash would have been confined to the linear areas where the tape touched his skin.

Dissolving sutures, such as those used in this case, can provoke a “suture granuloma”—essentially a foreign body reaction to the suture material (choice “b”). But this would have caused a focal area of swelling and redness, and very possibly a show of pus.

Postop wound infections (choice “c”) are also quite common. However, they would not manifest solely with itching in a papulovesicular rash surrounding the wound. Had infection developed, the redness would have been broad-based, with ill-defined margins, and the patient’s complaint would have been of pain, not itching. No vesicles would have been seen with bacterial infection.

DISCUSSION

This case illustrates the phenomenon of “treatment as problem,” in which the medication the patient applies becomes more problematic than the condition being addressed. Reactions to the neomycin in triple-antibiotic ointment are common but still provoke considerable worry on the part of patients and providers alike, especially when mistaken for “infection.”

This patient, like many, was dubious of the diagnosis, pointing out that he had used this same topical medication on many occasions without incident (though not recently). What he didn’t know is that it takes repeated exposure to a given allergen to develop T-memory cells that eventually begin to react. This same phenomenon is seen with poison ivy; patients will recall the ability, as a child, to practically wallow in poison ivy with impunity, making them doubtful about being allergic to it as an adult.

Neomycin, an aminoglycoside with a fairly wide spectrum of antibacterial activity, was first noted as a contact allergen in 1952. It is such a notorious offender that it was named Allergen of the Year in 2010 by the American Contact Dermatology Society.

For the past 20 years, 7% to 13% of patch tests surveyed were positive for neomycin. For reasons not entirely clear, Americans older than 60 are 150% more likely to experience a reaction to neomycin than are younger patients. (It could simply be that they’ve had more chances for exposure.)

In another interesting twist, the ointment vehicle appears to play a role. A reaction to this preparation is considerably more likely than to the same drug in other forms (eg, powders, solutions, creams). This is true of most medications, such as topical steroids, which are effectively self-occluded by this vehicle.

Persons with impaired barrier function, such as those with atopic dermatitis or whose skin has been prepped for surgery, appear to be at increased risk for these types of contact dermatoses.

Though there are other items in the differential, the configuration of the papulovesicular rash and the sole symptom of itching are essentially pathognomic for contact dermatitis. Besides the use of potent topical steroids for a few days, the real “cure” for this problem is for the patient to switch to “double-antibiotic” creams or ointments that do not include neomycin. 

ANSWER
The correct answer is pityriasis rosea (choice “b”), a common and very distinctive eruption related to human herpesvirus 6 and 7.

Allergic reaction to methotrexate (choice “a”), while far from unknown, does not resemble pityriasis rosea. It also would not be limited to such a relatively small area.

Pityriasis rosea is often designated as “fungal infection” (choice “c”) by the uninitiated. However, the lesions of dermatophytosis would be round, with a leading scaly edge, and unlikely to be found in this distribution.

Secondary syphilis (choice “d”) is a major item in the pityriasis rosea differential, but it almost always involves the palms and soles and the lesions would be round (not oval) scaly brown papules. Furthermore, assuming we have an honest patient, we’re also missing a source for sexually transmitted infection.

DISCUSSION
One could hardly ask for a more classic case of pityriasis rosea (PR), which primarily affects patients ages 14 to 40. Alas, that being said, one cannot depend on seeing all these clues in every PR patient.

For example, the herald patch (also known as the mother patch) is missing in at least half of cases. In others, the lesions are smaller, sparser, and more papular (especially in young black patients). The condition may even be confined to intertriginous areas (eg, the groin and/or axillae); this is known as inverse PR.

While salmon-colored scaly lesions are considered a classic presentation, PR can present with darker ovoid macules that have minimal scale and, rarely, become bullous. Involvement above the neck is rare.

What is consistent and dependable among signs of PR is the centripetal scale, seen even in the smallest lesions. This scale is so fine that the old dermatology texts called it “cigarette paper” scale or “scurf.”

After decades of speculation, researchers finally provided strong evidence of the probable cause  of PR: replication of human herpesvirus 6 and 7, present in mono-
nuclear cells of lesional skin. Though universally acquired in childhood, these viruses are thought to remain latent until reactivated, leading to viremia.

Itching can be moderately severe in a minority of cases. Most patients, such as this one, are not bothered much by the condition once they understand its self-limited nature. They usually are not happy, however, to learn that it could persist for nine weeks or more, whether treated or not.

UV light exposure can be helpful in hastening PR’s departure, and topical corticosteroids (class III or IV; eg, triamcinolone 0.1% cream) can help control the itching. Neither oral nor topical antihistamines will help, since PR is not a histamine-mediated problem.

If the diagnosis is in doubt, a punch biopsy could at least rule out the more serious items in the differential, which include syphilis, drug rash, and psoriasis. In cases in which fungal origin is a possibility, a quick KOH prep will settle the issue. However, it must be remembered that one doesn’t just “get” a fungal infection. There has to be a source (animal, child), and that source is usually identified with minimal history taking.

ANSWER
The correct answer is pityriasis rosea (choice “b”), a common and very distinctive eruption related to human herpesvirus 6 and 7.

Allergic reaction to methotrexate (choice “a”), while far from unknown, does not resemble pityriasis rosea. It also would not be limited to such a relatively small area.

Pityriasis rosea is often designated as “fungal infection” (choice “c”) by the uninitiated. However, the lesions of dermatophytosis would be round, with a leading scaly edge, and unlikely to be found in this distribution.

Secondary syphilis (choice “d”) is a major item in the pityriasis rosea differential, but it almost always involves the palms and soles and the lesions would be round (not oval) scaly brown papules. Furthermore, assuming we have an honest patient, we’re also missing a source for sexually transmitted infection.

DISCUSSION
One could hardly ask for a more classic case of pityriasis rosea (PR), which primarily affects patients ages 14 to 40. Alas, that being said, one cannot depend on seeing all these clues in every PR patient.

For example, the herald patch (also known as the mother patch) is missing in at least half of cases. In others, the lesions are smaller, sparser, and more papular (especially in young black patients). The condition may even be confined to intertriginous areas (eg, the groin and/or axillae); this is known as inverse PR.

While salmon-colored scaly lesions are considered a classic presentation, PR can present with darker ovoid macules that have minimal scale and, rarely, become bullous. Involvement above the neck is rare.

What is consistent and dependable among signs of PR is the centripetal scale, seen even in the smallest lesions. This scale is so fine that the old dermatology texts called it “cigarette paper” scale or “scurf.”

After decades of speculation, researchers finally provided strong evidence of the probable cause  of PR: replication of human herpesvirus 6 and 7, present in mono-
nuclear cells of lesional skin. Though universally acquired in childhood, these viruses are thought to remain latent until reactivated, leading to viremia.

Itching can be moderately severe in a minority of cases. Most patients, such as this one, are not bothered much by the condition once they understand its self-limited nature. They usually are not happy, however, to learn that it could persist for nine weeks or more, whether treated or not.

UV light exposure can be helpful in hastening PR’s departure, and topical corticosteroids (class III or IV; eg, triamcinolone 0.1% cream) can help control the itching. Neither oral nor topical antihistamines will help, since PR is not a histamine-mediated problem.

If the diagnosis is in doubt, a punch biopsy could at least rule out the more serious items in the differential, which include syphilis, drug rash, and psoriasis. In cases in which fungal origin is a possibility, a quick KOH prep will settle the issue. However, it must be remembered that one doesn’t just “get” a fungal infection. There has to be a source (animal, child), and that source is usually identified with minimal history taking.

ANSWER
The correct answer is pityriasis rosea (choice “b”), a common and very distinctive eruption related to human herpesvirus 6 and 7.

Allergic reaction to methotrexate (choice “a”), while far from unknown, does not resemble pityriasis rosea. It also would not be limited to such a relatively small area.

Pityriasis rosea is often designated as “fungal infection” (choice “c”) by the uninitiated. However, the lesions of dermatophytosis would be round, with a leading scaly edge, and unlikely to be found in this distribution.

Secondary syphilis (choice “d”) is a major item in the pityriasis rosea differential, but it almost always involves the palms and soles and the lesions would be round (not oval) scaly brown papules. Furthermore, assuming we have an honest patient, we’re also missing a source for sexually transmitted infection.

DISCUSSION
One could hardly ask for a more classic case of pityriasis rosea (PR), which primarily affects patients ages 14 to 40. Alas, that being said, one cannot depend on seeing all these clues in every PR patient.

For example, the herald patch (also known as the mother patch) is missing in at least half of cases. In others, the lesions are smaller, sparser, and more papular (especially in young black patients). The condition may even be confined to intertriginous areas (eg, the groin and/or axillae); this is known as inverse PR.

While salmon-colored scaly lesions are considered a classic presentation, PR can present with darker ovoid macules that have minimal scale and, rarely, become bullous. Involvement above the neck is rare.

What is consistent and dependable among signs of PR is the centripetal scale, seen even in the smallest lesions. This scale is so fine that the old dermatology texts called it “cigarette paper” scale or “scurf.”

After decades of speculation, researchers finally provided strong evidence of the probable cause  of PR: replication of human herpesvirus 6 and 7, present in mono-
nuclear cells of lesional skin. Though universally acquired in childhood, these viruses are thought to remain latent until reactivated, leading to viremia.

Itching can be moderately severe in a minority of cases. Most patients, such as this one, are not bothered much by the condition once they understand its self-limited nature. They usually are not happy, however, to learn that it could persist for nine weeks or more, whether treated or not.

UV light exposure can be helpful in hastening PR’s departure, and topical corticosteroids (class III or IV; eg, triamcinolone 0.1% cream) can help control the itching. Neither oral nor topical antihistamines will help, since PR is not a histamine-mediated problem.

If the diagnosis is in doubt, a punch biopsy could at least rule out the more serious items in the differential, which include syphilis, drug rash, and psoriasis. In cases in which fungal origin is a possibility, a quick KOH prep will settle the issue. However, it must be remembered that one doesn’t just “get” a fungal infection. There has to be a source (animal, child), and that source is usually identified with minimal history taking.

ANSWER

Admittedly, this is a bit of a trick question—but with a good teaching point to make. A course of oral fluconazole (choice “a”) is futile, since there’s no reason to think this problem is yeast-driven and since the patient has already demonstrated a lack of response to topical imidazoles.

Punch biopsy (choice “b”) would be a good choice, but not in this area, where it could quickly become a bigger problem than the one the patient presented with. Sutures would not likely hold the biopsy wound together, and resultant infection is all too likely.

A KOH test to detect fungal or yeast elements (choice “c”) is unlikely to shed any light on the problem, given the lack of response to antifungal creams. Finally, there’s no reason to suspect a bacterial origin, so oral antibiotics such as cephalexin (choice “d”) would be useless (and had already been tried unsuccessfully).

The correct answer is none of the above (choice “e”).

DISCUSSION

This case illustrates why dermatology seems so maddeningly difficult to the uninitiated. Any experienced derm provider would know the correct diagnosis, lichen sclerosus et atrophicus (LS&A), because it presents in such a distinctive way (in limited locations, predominantly in women) and because the differential is so limited. But if you’ve never heard of LS&A, you’re unlikely to diagnose it, let alone know how to treat it.

LS&A is an inflammatory condition of unknown origin that affects the upper epidermis. It can present in extragenital locations (particularly shoulders and legs) but is far more common in genital areas. As exhibited in this case, it presents with well-defined pigment loss, which is especially easy to see in patients with darker skin.

Although more commonly seen in women, LS&A can occur in men, usually manifesting on the penile glans and distal foreskin of uncircumcised patients. The dry atrophic changes seen on the glans can lead to stenosis of the urethral meatus and, proximally, to adhesions (phimosis) of the foreskin. (This condition was termed balanitis xerotica obliterans [BXO] long before its pathologic process was determined to be identical to LS&A’s. Tissue specimens obtained during circumcisions performed for chronic phimosis often yield evidence of BXO.)

In women, untreated chronic LS&A can lead to sclerotic changes in and around the urethra and labia minora and can cause introital stenosis. This case is a bit atypical; LS&A more often manifests in perivaginal and perirectal areas, where the intense hypopigmentation produces a classic “figure eight” appearance.

The differential includes lichen simplex chronicus, psoriasis, lichen planus, contact/irritant dermatitis, and seborrhea. Often, biopsy is necessary and appropriate to settle the issue, other factors being equal.

TREATMENT/PROGNOSIS

The patient was given a prescription for clobetasol 0.05% ointment for twice-daily application Monday through Friday (and no application for two consecutive days—in this case, the weekend—per week). Studies have established the efficacy and safety of this treatment regimen.

In a month or two, application can be reduced to once or twice a week to control the condition.

ANSWER

Admittedly, this is a bit of a trick question—but with a good teaching point to make. A course of oral fluconazole (choice “a”) is futile, since there’s no reason to think this problem is yeast-driven and since the patient has already demonstrated a lack of response to topical imidazoles.

Punch biopsy (choice “b”) would be a good choice, but not in this area, where it could quickly become a bigger problem than the one the patient presented with. Sutures would not likely hold the biopsy wound together, and resultant infection is all too likely.

A KOH test to detect fungal or yeast elements (choice “c”) is unlikely to shed any light on the problem, given the lack of response to antifungal creams. Finally, there’s no reason to suspect a bacterial origin, so oral antibiotics such as cephalexin (choice “d”) would be useless (and had already been tried unsuccessfully).

The correct answer is none of the above (choice “e”).

DISCUSSION

This case illustrates why dermatology seems so maddeningly difficult to the uninitiated. Any experienced derm provider would know the correct diagnosis, lichen sclerosus et atrophicus (LS&A), because it presents in such a distinctive way (in limited locations, predominantly in women) and because the differential is so limited. But if you’ve never heard of LS&A, you’re unlikely to diagnose it, let alone know how to treat it.

LS&A is an inflammatory condition of unknown origin that affects the upper epidermis. It can present in extragenital locations (particularly shoulders and legs) but is far more common in genital areas. As exhibited in this case, it presents with well-defined pigment loss, which is especially easy to see in patients with darker skin.

Although more commonly seen in women, LS&A can occur in men, usually manifesting on the penile glans and distal foreskin of uncircumcised patients. The dry atrophic changes seen on the glans can lead to stenosis of the urethral meatus and, proximally, to adhesions (phimosis) of the foreskin. (This condition was termed balanitis xerotica obliterans [BXO] long before its pathologic process was determined to be identical to LS&A’s. Tissue specimens obtained during circumcisions performed for chronic phimosis often yield evidence of BXO.)

In women, untreated chronic LS&A can lead to sclerotic changes in and around the urethra and labia minora and can cause introital stenosis. This case is a bit atypical; LS&A more often manifests in perivaginal and perirectal areas, where the intense hypopigmentation produces a classic “figure eight” appearance.

The differential includes lichen simplex chronicus, psoriasis, lichen planus, contact/irritant dermatitis, and seborrhea. Often, biopsy is necessary and appropriate to settle the issue, other factors being equal.

TREATMENT/PROGNOSIS

The patient was given a prescription for clobetasol 0.05% ointment for twice-daily application Monday through Friday (and no application for two consecutive days—in this case, the weekend—per week). Studies have established the efficacy and safety of this treatment regimen.

In a month or two, application can be reduced to once or twice a week to control the condition.

ANSWER

Admittedly, this is a bit of a trick question—but with a good teaching point to make. A course of oral fluconazole (choice “a”) is futile, since there’s no reason to think this problem is yeast-driven and since the patient has already demonstrated a lack of response to topical imidazoles.

Punch biopsy (choice “b”) would be a good choice, but not in this area, where it could quickly become a bigger problem than the one the patient presented with. Sutures would not likely hold the biopsy wound together, and resultant infection is all too likely.

A KOH test to detect fungal or yeast elements (choice “c”) is unlikely to shed any light on the problem, given the lack of response to antifungal creams. Finally, there’s no reason to suspect a bacterial origin, so oral antibiotics such as cephalexin (choice “d”) would be useless (and had already been tried unsuccessfully).

The correct answer is none of the above (choice “e”).

DISCUSSION

This case illustrates why dermatology seems so maddeningly difficult to the uninitiated. Any experienced derm provider would know the correct diagnosis, lichen sclerosus et atrophicus (LS&A), because it presents in such a distinctive way (in limited locations, predominantly in women) and because the differential is so limited. But if you’ve never heard of LS&A, you’re unlikely to diagnose it, let alone know how to treat it.

LS&A is an inflammatory condition of unknown origin that affects the upper epidermis. It can present in extragenital locations (particularly shoulders and legs) but is far more common in genital areas. As exhibited in this case, it presents with well-defined pigment loss, which is especially easy to see in patients with darker skin.

Although more commonly seen in women, LS&A can occur in men, usually manifesting on the penile glans and distal foreskin of uncircumcised patients. The dry atrophic changes seen on the glans can lead to stenosis of the urethral meatus and, proximally, to adhesions (phimosis) of the foreskin. (This condition was termed balanitis xerotica obliterans [BXO] long before its pathologic process was determined to be identical to LS&A’s. Tissue specimens obtained during circumcisions performed for chronic phimosis often yield evidence of BXO.)

In women, untreated chronic LS&A can lead to sclerotic changes in and around the urethra and labia minora and can cause introital stenosis. This case is a bit atypical; LS&A more often manifests in perivaginal and perirectal areas, where the intense hypopigmentation produces a classic “figure eight” appearance.

The differential includes lichen simplex chronicus, psoriasis, lichen planus, contact/irritant dermatitis, and seborrhea. Often, biopsy is necessary and appropriate to settle the issue, other factors being equal.

TREATMENT/PROGNOSIS

The patient was given a prescription for clobetasol 0.05% ointment for twice-daily application Monday through Friday (and no application for two consecutive days—in this case, the weekend—per week). Studies have established the efficacy and safety of this treatment regimen.

In a month or two, application can be reduced to once or twice a week to control the condition.

ANSWER
The correct answer is tuberous sclerosis (choice “d”), a genetic disorder affecting cellular differentiation and proliferation. As a result, hamartomas commonly form in organs such as the brain.

Von Recklinghausen disease (choice “a”; also known as neurofibromatosis type 1) presents with hyperpigmented macules and patches called café au lait macules. These and other findings differentiate it considerably from tuberous sclerosis.

“No unifying explanation” (choice “b”) is incorrect, because, as stated above, there is a unifying explanation for these findings!

Vitiligo (choice “c”) involves hypopigmented macules and patches. However, it does not present with some of the other findings seen in this case.

DISCUSSION
Tuberous sclerosis was first described in 1862 by von Recklinghausen, who noted the collection of findings we now term tuberous sclerosis complex (TSC) due to the wide variation in presentation.

In the United States, TSC occurs in an estimated one in 6,000 to one in 30,000 newborns. Usually, it manifests when the child is between ages 2 and 6, but genetic penetrance is highly variable—a major reason for the shift to the use of the term complex with this condition. (This case, with its late presentation, illustrates this variability.)

In about 60% of cases, TSC is transmitted in autosomal dominant mode, although at least 20% of cases may be due to spontaneous mutations. It has not shown any racial or gender predilections. Up to 90% of TSC patients will present with seizures, and 60% to 70% of those affected will demonstrate some developmental disability.

Skin is affected in at least 70% of TSC cases. This patient typifies the common dermatologic findings: dart-shaped hypopigmented macules (known as mountain ash leaf spots) and fleshy facial papules in the nasolabial region (originally called adenoma sebaceum and now called angiofibromas). Periungal fibromas are also common. Other major diagnostic criteria for TSC include cortical tubers seen on imaging and retinal hamartomas. Minor diagnostic criteria include pits in dental enamel and gingival fibromas.

Definitive diagnosis depends on identification of either two major manifestations or one major and two minor findings. There are no blood tests to confirm the diagnosis. In terms of treatment, the various elements that comprise TSC can be dealt with (eg, control of seizures and destruction or modification of skin lesions).

This patient received a diagnosis of TSC. She was returned to her primary care provider, who referred her for additional imaging of her lungs and heart and for ophthalmologic evaluation of her retinas. Genetic counseling was also arranged. With her seizures under control, she was able to continue matriculation through high school.

ANSWER
The correct answer is tuberous sclerosis (choice “d”), a genetic disorder affecting cellular differentiation and proliferation. As a result, hamartomas commonly form in organs such as the brain.

Von Recklinghausen disease (choice “a”; also known as neurofibromatosis type 1) presents with hyperpigmented macules and patches called café au lait macules. These and other findings differentiate it considerably from tuberous sclerosis.

“No unifying explanation” (choice “b”) is incorrect, because, as stated above, there is a unifying explanation for these findings!

Vitiligo (choice “c”) involves hypopigmented macules and patches. However, it does not present with some of the other findings seen in this case.

DISCUSSION
Tuberous sclerosis was first described in 1862 by von Recklinghausen, who noted the collection of findings we now term tuberous sclerosis complex (TSC) due to the wide variation in presentation.

In the United States, TSC occurs in an estimated one in 6,000 to one in 30,000 newborns. Usually, it manifests when the child is between ages 2 and 6, but genetic penetrance is highly variable—a major reason for the shift to the use of the term complex with this condition. (This case, with its late presentation, illustrates this variability.)

In about 60% of cases, TSC is transmitted in autosomal dominant mode, although at least 20% of cases may be due to spontaneous mutations. It has not shown any racial or gender predilections. Up to 90% of TSC patients will present with seizures, and 60% to 70% of those affected will demonstrate some developmental disability.

Skin is affected in at least 70% of TSC cases. This patient typifies the common dermatologic findings: dart-shaped hypopigmented macules (known as mountain ash leaf spots) and fleshy facial papules in the nasolabial region (originally called adenoma sebaceum and now called angiofibromas). Periungal fibromas are also common. Other major diagnostic criteria for TSC include cortical tubers seen on imaging and retinal hamartomas. Minor diagnostic criteria include pits in dental enamel and gingival fibromas.

Definitive diagnosis depends on identification of either two major manifestations or one major and two minor findings. There are no blood tests to confirm the diagnosis. In terms of treatment, the various elements that comprise TSC can be dealt with (eg, control of seizures and destruction or modification of skin lesions).

This patient received a diagnosis of TSC. She was returned to her primary care provider, who referred her for additional imaging of her lungs and heart and for ophthalmologic evaluation of her retinas. Genetic counseling was also arranged. With her seizures under control, she was able to continue matriculation through high school.

ANSWER
The correct answer is tuberous sclerosis (choice “d”), a genetic disorder affecting cellular differentiation and proliferation. As a result, hamartomas commonly form in organs such as the brain.

Von Recklinghausen disease (choice “a”; also known as neurofibromatosis type 1) presents with hyperpigmented macules and patches called café au lait macules. These and other findings differentiate it considerably from tuberous sclerosis.

“No unifying explanation” (choice “b”) is incorrect, because, as stated above, there is a unifying explanation for these findings!

Vitiligo (choice “c”) involves hypopigmented macules and patches. However, it does not present with some of the other findings seen in this case.

DISCUSSION
Tuberous sclerosis was first described in 1862 by von Recklinghausen, who noted the collection of findings we now term tuberous sclerosis complex (TSC) due to the wide variation in presentation.

In the United States, TSC occurs in an estimated one in 6,000 to one in 30,000 newborns. Usually, it manifests when the child is between ages 2 and 6, but genetic penetrance is highly variable—a major reason for the shift to the use of the term complex with this condition. (This case, with its late presentation, illustrates this variability.)

In about 60% of cases, TSC is transmitted in autosomal dominant mode, although at least 20% of cases may be due to spontaneous mutations. It has not shown any racial or gender predilections. Up to 90% of TSC patients will present with seizures, and 60% to 70% of those affected will demonstrate some developmental disability.

Skin is affected in at least 70% of TSC cases. This patient typifies the common dermatologic findings: dart-shaped hypopigmented macules (known as mountain ash leaf spots) and fleshy facial papules in the nasolabial region (originally called adenoma sebaceum and now called angiofibromas). Periungal fibromas are also common. Other major diagnostic criteria for TSC include cortical tubers seen on imaging and retinal hamartomas. Minor diagnostic criteria include pits in dental enamel and gingival fibromas.

Definitive diagnosis depends on identification of either two major manifestations or one major and two minor findings. There are no blood tests to confirm the diagnosis. In terms of treatment, the various elements that comprise TSC can be dealt with (eg, control of seizures and destruction or modification of skin lesions).

This patient received a diagnosis of TSC. She was returned to her primary care provider, who referred her for additional imaging of her lungs and heart and for ophthalmologic evaluation of her retinas. Genetic counseling was also arranged. With her seizures under control, she was able to continue matriculation through high school.

ANSWER

The correct answer is eruptive xanthomata (choice “b”) caused by an accumulation of lipid-filled macrophages as a result of pathologic levels of serum triglyceride—a situation discussed more fully below.

Neurofibromatosis type I (choice “a”), also known as von Recklinghausen disease, can present with multiple intradermal nodules. However, it usually appears in the second or third decade of life, with lesions that are fixed and soft. Biopsy would have confirmed this diagnosis.

Diabetic dermopathy (choice “c”) manifests with atrophic patches on anterior tibial skin. The patches occasionally become superficially eroded but do not resemble this patient’s lesions at all.

Juvenile xanthogranuloma (choice “d”) usually presents on children as a solitary yellowish brown papule. It can resemble eruptive xanthomata histologically but not clinically.

DISCUSSION

Eruptive xanthomata (EX) are relatively common, manifesting rapidly as papules and nodules, most frequently in the setting of hypertriglyceridemia. The latter can be familial and may be worsened by poorly controlled diabetes. Persons with Fredrickson types I, IV, and V hyperlipidemia are especially prone to EX.

As might be expected, patients with EX are at risk for several associated morbidities, including acute pancreatitis (especially in childhood cases) and atherosclerotic vessel disease. EX have also been associated with hypothyroid states and nephrotic syndromes.

Elevations in cholesterol, with normal triglyceride levels, can be associated with several types of xanthoma, including plane xanthomas and xanthelasma. The latter, often benign, can manifest in a normolipemic patient as well (necessitating a problem-directed history, physical, and lipid check).

Biopsy is often required to confirm the diagnosis of EX. As in this case, it typically shows monotonous collections of lipid-laden macrophages. Frozen sections of EX can be successfully stained for lipids, but routine processing of specimens effectively removes any lipids, replacing them with paraffin.

TREATMENT

Treatment entails controlling lipids with medication (fenofibrate), diet, and exercise and getting diabetes under control, as indicated. It is also essential to assess for atherosclerotic vessel disease and rule out pancreatitis.

Within a month of institution of treatment, this patient’s lesions had all but disappeared. His serum amylase and lipase were within normal limits, and testing for atherosclerotic vessel disease was pending.

Click here for more DermaDiagnosis cases, including 
• The Value of Certainty in Diagnosis
• A Purplish Rash on the Instep
• Hair Loss at a Very Young Age.

ANSWER

The correct answer is eruptive xanthomata (choice “b”) caused by an accumulation of lipid-filled macrophages as a result of pathologic levels of serum triglyceride—a situation discussed more fully below.

Neurofibromatosis type I (choice “a”), also known as von Recklinghausen disease, can present with multiple intradermal nodules. However, it usually appears in the second or third decade of life, with lesions that are fixed and soft. Biopsy would have confirmed this diagnosis.

Diabetic dermopathy (choice “c”) manifests with atrophic patches on anterior tibial skin. The patches occasionally become superficially eroded but do not resemble this patient’s lesions at all.

Juvenile xanthogranuloma (choice “d”) usually presents on children as a solitary yellowish brown papule. It can resemble eruptive xanthomata histologically but not clinically.

DISCUSSION

Eruptive xanthomata (EX) are relatively common, manifesting rapidly as papules and nodules, most frequently in the setting of hypertriglyceridemia. The latter can be familial and may be worsened by poorly controlled diabetes. Persons with Fredrickson types I, IV, and V hyperlipidemia are especially prone to EX.

As might be expected, patients with EX are at risk for several associated morbidities, including acute pancreatitis (especially in childhood cases) and atherosclerotic vessel disease. EX have also been associated with hypothyroid states and nephrotic syndromes.

Elevations in cholesterol, with normal triglyceride levels, can be associated with several types of xanthoma, including plane xanthomas and xanthelasma. The latter, often benign, can manifest in a normolipemic patient as well (necessitating a problem-directed history, physical, and lipid check).

Biopsy is often required to confirm the diagnosis of EX. As in this case, it typically shows monotonous collections of lipid-laden macrophages. Frozen sections of EX can be successfully stained for lipids, but routine processing of specimens effectively removes any lipids, replacing them with paraffin.

TREATMENT

Treatment entails controlling lipids with medication (fenofibrate), diet, and exercise and getting diabetes under control, as indicated. It is also essential to assess for atherosclerotic vessel disease and rule out pancreatitis.

Within a month of institution of treatment, this patient’s lesions had all but disappeared. His serum amylase and lipase were within normal limits, and testing for atherosclerotic vessel disease was pending.

Click here for more DermaDiagnosis cases, including 
• The Value of Certainty in Diagnosis
• A Purplish Rash on the Instep
• Hair Loss at a Very Young Age.

ANSWER

The correct answer is eruptive xanthomata (choice “b”) caused by an accumulation of lipid-filled macrophages as a result of pathologic levels of serum triglyceride—a situation discussed more fully below.

Neurofibromatosis type I (choice “a”), also known as von Recklinghausen disease, can present with multiple intradermal nodules. However, it usually appears in the second or third decade of life, with lesions that are fixed and soft. Biopsy would have confirmed this diagnosis.

Diabetic dermopathy (choice “c”) manifests with atrophic patches on anterior tibial skin. The patches occasionally become superficially eroded but do not resemble this patient’s lesions at all.

Juvenile xanthogranuloma (choice “d”) usually presents on children as a solitary yellowish brown papule. It can resemble eruptive xanthomata histologically but not clinically.

DISCUSSION

Eruptive xanthomata (EX) are relatively common, manifesting rapidly as papules and nodules, most frequently in the setting of hypertriglyceridemia. The latter can be familial and may be worsened by poorly controlled diabetes. Persons with Fredrickson types I, IV, and V hyperlipidemia are especially prone to EX.

As might be expected, patients with EX are at risk for several associated morbidities, including acute pancreatitis (especially in childhood cases) and atherosclerotic vessel disease. EX have also been associated with hypothyroid states and nephrotic syndromes.

Elevations in cholesterol, with normal triglyceride levels, can be associated with several types of xanthoma, including plane xanthomas and xanthelasma. The latter, often benign, can manifest in a normolipemic patient as well (necessitating a problem-directed history, physical, and lipid check).

Biopsy is often required to confirm the diagnosis of EX. As in this case, it typically shows monotonous collections of lipid-laden macrophages. Frozen sections of EX can be successfully stained for lipids, but routine processing of specimens effectively removes any lipids, replacing them with paraffin.

TREATMENT

Treatment entails controlling lipids with medication (fenofibrate), diet, and exercise and getting diabetes under control, as indicated. It is also essential to assess for atherosclerotic vessel disease and rule out pancreatitis.

Within a month of institution of treatment, this patient’s lesions had all but disappeared. His serum amylase and lipase were within normal limits, and testing for atherosclerotic vessel disease was pending.

Click here for more DermaDiagnosis cases, including 
• The Value of Certainty in Diagnosis
• A Purplish Rash on the Instep
• Hair Loss at a Very Young Age.