Red Light for Acne

Several light devices based on red light–emitting diodes (LEDs) have made their way to the market in recent years. Although red light is not truly a cosmeceutical, it is a significant emerging adjuvant therapy that, like blue light, has been studied in comparison to and in conjunction with topical options primarily to treat acne. Of course, acne is the most common skin disorder prompting visits to the dermatologist, with an estimated 85% of adolescents affected, many into adulthood (J. Am. Acad. Dermatol. 2008;58:56-9).

This discussion will consider red light when used alone and when used in combination with blue light. Blue light is the most effective light to target Propionibacterium acnes (specifically at wavelengths of 407-420 nm). However, many devices are utilizing red light because it has a purported anti-inflammatory effect and penetrates deeper into the skin (Dermatol. Ther. 2005;18:253-66).

Erythrasma

Darras-Vercambre et al. evaluated the effects of red light for the treatment of erythrasma (a superficial skin infection provoked by Corynebacterium minutissimum) in 13 patients. One treatment (80 J/cm²) by red light (broadband, peak at 635 nm) without exogenous photosensitizing molecules was administered to each subject. Therapy was effective and well tolerated, with three patients experiencing complete recovery, and significant reduction of lesions in most other cases. The authors noted that the key to their study, given the absence of an exogenous photosensitizing agent, was capitalizing on the presence of porphyrins in the lesions. They concluded that the use of red light alone for this localized infection is easy and inexpensive, but that an optimal method has not yet been established (Photodermatol. Photoimmunol. Photomed. 2006;22:153-6).

Acne

In 2007, Na and Suh evaluated the efficacy of red light phototherapy with a portable device in 28 volunteers with mild to moderate acne in a split-face randomized trial. Phototherapy was performed twice daily for 15 minutes for a total of 8 weeks to one side of the face. The investigators concluded that red light phototherapy alone is an effective therapeutic option for acne, as they noted significant reductions in noninflammatory and inflammatory lesion counts on the treated side versus the untreated side, a drop from 3.9 to 1.9 in the visual analog scale on the treatment side, and significant disparities between the treatment and control sides after 8 weeks (Dermatol. Surg. 2007;33:1228-33, discussion 1233).

A 2006 article in the British Journal of Dermatology reported good clinical results from acne treatment with photodynamic therapy (PDT) using methyl aminolevulinate (MAL) and red light, but there were adverse side effects that prompted 7 of 19 subjects to discontinue the study (Br. J. Dermatol. 2006;154:969-76). In response to the study, Mavilia et al. wrote a letter to the journal acknowledging their more effective combination therapy using a lower concentration of MAL and low doses of red light. All 16 patients completed the study, in which the count of inflammatory lesions fell an average of 66% with mild but tolerable side effects, including a subtle sensation of heat, then minimal erythema during the procedure and slight scaling that began 3 days after treatment (Br. J. Dermatol. 2007;157:810-1).

In a small study of patients with moderate facial acne, Zane et al. exposed 15 women to 20 J/cm² of broadband red light (600-750 nm) twice weekly for 4 weeks. They also measured skin sebum, pH, hydration, and transepidermal water loss (TEWL). Untreated lesions of the trunk served as controls. The investigators found the treatment safe, well tolerated, and effective, with significant improvement in acne lesions and reduction of sebum excretion and TEWL after 4 weeks of therapy and at the 3-month follow-up visit. They speculated that the improvement was due to the decreased colonization of P. acnes, decimated by photoactivated endogenous porphyrin, and concluded that this inexpensive therapy warrants inclusion among treatment options for moderate acne (Photodermatol. Photoimmunol. Photomed. 2008;24:244-8).

In a 2009 study of 19 patients with moderate to severe facial acne who received a single treatment of low-dose, red-light PDT on the left cheek and MAL 3 hours before red light on the right cheek, both therapies yielded significant reductions in acne score. Red light was found to be as effective as MAL-PDT (Acta Derm. Venereol. 2009;89:372-8).

Combined Blue and Red Light Phototherapy

In 2006, Goldberg and Russell evaluated the combination of blue (415 nm) and red (633 nm) LED phototherapy in 24 patients with Fitzpatrick skin types II-V and mild to severe symmetric facial acne. Twenty-two patients completed the trial, which included two sessions per week (separated by 3 days) alternating between blue and red light for a total of eight sessions. Mild microdermabrasion was used at the start of each session. The mean decrease in lesion count was significant after 4 weeks (46%) and 12 weeks (81%). Inflammatory lesions responded better than did noninflammatory ones, and severe acne responded slightly better than mild acne. The investigators concluded that the combination of blue and red LED phototherapy is free of side effects and pain, and exhibits great potential for the treatment of mild to severe acne (J. Cosmet. Laser Ther. 2006;8:71-5).

In 2007, Lee et al. set out to examine the efficacy of combining blue and red LED phototherapy for acne in a study of 24 patients with mild to moderately severe facial acne. Twice weekly for 4 weeks, patients were treated with quasi-monochromatic LED devices, alternating blue (415 nm) and red (633 nm) light. Fourteen patients self-reported improvements in skin tone and texture. Improvements in noninflammatory and inflammatory lesions were substantial (34.28% and 77.93%, respectively). The researchers concluded that combined blue and red LED phototherapy is a safe and effective option, especially for papulopustular acne (Lasers Surg. Med. 2007;39:180-8).

In 2009, Sadick evaluated the efficacy of the combination of blue (415 nm) and near-infrared (830 nm) LED therapy for moderate acne in 13 females and 4 males ranging in skin type from II to VI and in Burton acne grade at baseline from 1 to 5. Twice-weekly 20-minute sessions were conducted for 4 weeks, alternating between blue and near-infrared light. Eleven patients exhibited improvement ranging from 0% to 83.3%, and 6 patients discontinued the study. A decreasing trend was observed in the Burton grade. Noninflammatory lesion counts improved in seven patients but increased in four. Sadick noted that these results paled in comparison to the effectiveness of the blue and red combination at lowering inflammatory lesions seen previously, but encouraged the study of the combination phototherapy in a much larger population (J. Cosmet. Laser Ther. 2009;11:125-8).

Several recent reviews have found that red light–activated MAL-PDT, the combination of blue and red light, and aminolevulinic acid as a photosensitizing agent before treatment with blue light, red light, or the 595-nm pulsed dye laser are among the most promising evidence-based laser- and light-based therapies for acne (Semin. Cutan. Med. Surg. 2008;27:207-11; J. Eur. Acad. Dermatol. Venereol. 2008;22:267-78; Dermatol. Surg. 2007;33:1005-26).

In a systematic literature review of randomized controlled trials of light and laser therapies for acne vulgaris (using the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, PsycINFO, LILACS, ISI Science Citation Index, and Dissertation Abstracts International), Hamilton et al. found that trials of blue light, blue-red light, and infrared radiation were more successful, especially when multiple treatments were used. Notably, blue-red light demonstrated better short-term effectiveness than did topical 5% benzoyl peroxide cream (Br. J. Dermatol. 2009;160:1273-85).

Kim and Armstrong have noted that blue light has been demonstrated to photoinactivate P. acnes, but it does not penetrate deeply into the skin. It is believed to work synergistically, however, with red light, which is less effective than blue light at exciting porphyrins but can reach deeper sebaceous glands and may impart an anti-inflammatory effect by inciting cytokine release from macrophages (Dermatol. Surg. 2007;33:1005-26). Indeed, Kim and Armstrong found that combined blue-red light therapy was more effective at lowering the number of inflammatory acne lesions than were benzoyl peroxide monotherapy and blue light monotherapy (Lasers Surg. Med. 1989;9:497-505).

Conclusions

A lengthy review of the literature and personal experience treating patients have convinced me that blue light is an effective treatment for acne. P. acnes is most susceptible to the blue light wavelengths of 407-420 nm. Addition of red light may help speed resolution of inflammatory lesions through an anti-inflammatory effect. Blue and red light devices are efficacious when used in the office if the devices deliver enough joules.

Many at-home devices and iPhone apps have hit the market. These are a great alternative to irritating topicals and antibiotics, and they may help increase compliance. However, many at-home light devices are too weak (do not emit enough joules), or emit a broad range of light (rather than 407-420 nm). The manufacturers of some of these products claim that the heat produced by the devices improves acne, but there is a paucity of research proving this point. In my opinion, using an at-home device twice a day that delivers 407-420 nm (with or without the addition of red light), and delivers enough joules (at least 25 J/cm²), is an effective method of treating acne. For comparison purposes, the in-office Omnilux delivers around 49 J/cm² but is used only two or three times per week. Know your wavelengths and joules when trying to decide which device to sell in your practice or recommend to patients.

Several light devices based on red light–emitting diodes (LEDs) have made their way to the market in recent years. Although red light is not truly a cosmeceutical, it is a significant emerging adjuvant therapy that, like blue light, has been studied in comparison to and in conjunction with topical options primarily to treat acne. Of course, acne is the most common skin disorder prompting visits to the dermatologist, with an estimated 85% of adolescents affected, many into adulthood (J. Am. Acad. Dermatol. 2008;58:56-9).

This discussion will consider red light when used alone and when used in combination with blue light. Blue light is the most effective light to target Propionibacterium acnes (specifically at wavelengths of 407-420 nm). However, many devices are utilizing red light because it has a purported anti-inflammatory effect and penetrates deeper into the skin (Dermatol. Ther. 2005;18:253-66).

Erythrasma

Darras-Vercambre et al. evaluated the effects of red light for the treatment of erythrasma (a superficial skin infection provoked by Corynebacterium minutissimum) in 13 patients. One treatment (80 J/cm²) by red light (broadband, peak at 635 nm) without exogenous photosensitizing molecules was administered to each subject. Therapy was effective and well tolerated, with three patients experiencing complete recovery, and significant reduction of lesions in most other cases. The authors noted that the key to their study, given the absence of an exogenous photosensitizing agent, was capitalizing on the presence of porphyrins in the lesions. They concluded that the use of red light alone for this localized infection is easy and inexpensive, but that an optimal method has not yet been established (Photodermatol. Photoimmunol. Photomed. 2006;22:153-6).

Acne

In 2007, Na and Suh evaluated the efficacy of red light phototherapy with a portable device in 28 volunteers with mild to moderate acne in a split-face randomized trial. Phototherapy was performed twice daily for 15 minutes for a total of 8 weeks to one side of the face. The investigators concluded that red light phototherapy alone is an effective therapeutic option for acne, as they noted significant reductions in noninflammatory and inflammatory lesion counts on the treated side versus the untreated side, a drop from 3.9 to 1.9 in the visual analog scale on the treatment side, and significant disparities between the treatment and control sides after 8 weeks (Dermatol. Surg. 2007;33:1228-33, discussion 1233).

A 2006 article in the British Journal of Dermatology reported good clinical results from acne treatment with photodynamic therapy (PDT) using methyl aminolevulinate (MAL) and red light, but there were adverse side effects that prompted 7 of 19 subjects to discontinue the study (Br. J. Dermatol. 2006;154:969-76). In response to the study, Mavilia et al. wrote a letter to the journal acknowledging their more effective combination therapy using a lower concentration of MAL and low doses of red light. All 16 patients completed the study, in which the count of inflammatory lesions fell an average of 66% with mild but tolerable side effects, including a subtle sensation of heat, then minimal erythema during the procedure and slight scaling that began 3 days after treatment (Br. J. Dermatol. 2007;157:810-1).

In a small study of patients with moderate facial acne, Zane et al. exposed 15 women to 20 J/cm² of broadband red light (600-750 nm) twice weekly for 4 weeks. They also measured skin sebum, pH, hydration, and transepidermal water loss (TEWL). Untreated lesions of the trunk served as controls. The investigators found the treatment safe, well tolerated, and effective, with significant improvement in acne lesions and reduction of sebum excretion and TEWL after 4 weeks of therapy and at the 3-month follow-up visit. They speculated that the improvement was due to the decreased colonization of P. acnes, decimated by photoactivated endogenous porphyrin, and concluded that this inexpensive therapy warrants inclusion among treatment options for moderate acne (Photodermatol. Photoimmunol. Photomed. 2008;24:244-8).

In a 2009 study of 19 patients with moderate to severe facial acne who received a single treatment of low-dose, red-light PDT on the left cheek and MAL 3 hours before red light on the right cheek, both therapies yielded significant reductions in acne score. Red light was found to be as effective as MAL-PDT (Acta Derm. Venereol. 2009;89:372-8).

Combined Blue and Red Light Phototherapy

In 2006, Goldberg and Russell evaluated the combination of blue (415 nm) and red (633 nm) LED phototherapy in 24 patients with Fitzpatrick skin types II-V and mild to severe symmetric facial acne. Twenty-two patients completed the trial, which included two sessions per week (separated by 3 days) alternating between blue and red light for a total of eight sessions. Mild microdermabrasion was used at the start of each session. The mean decrease in lesion count was significant after 4 weeks (46%) and 12 weeks (81%). Inflammatory lesions responded better than did noninflammatory ones, and severe acne responded slightly better than mild acne. The investigators concluded that the combination of blue and red LED phototherapy is free of side effects and pain, and exhibits great potential for the treatment of mild to severe acne (J. Cosmet. Laser Ther. 2006;8:71-5).

In 2007, Lee et al. set out to examine the efficacy of combining blue and red LED phototherapy for acne in a study of 24 patients with mild to moderately severe facial acne. Twice weekly for 4 weeks, patients were treated with quasi-monochromatic LED devices, alternating blue (415 nm) and red (633 nm) light. Fourteen patients self-reported improvements in skin tone and texture. Improvements in noninflammatory and inflammatory lesions were substantial (34.28% and 77.93%, respectively). The researchers concluded that combined blue and red LED phototherapy is a safe and effective option, especially for papulopustular acne (Lasers Surg. Med. 2007;39:180-8).

In 2009, Sadick evaluated the efficacy of the combination of blue (415 nm) and near-infrared (830 nm) LED therapy for moderate acne in 13 females and 4 males ranging in skin type from II to VI and in Burton acne grade at baseline from 1 to 5. Twice-weekly 20-minute sessions were conducted for 4 weeks, alternating between blue and near-infrared light. Eleven patients exhibited improvement ranging from 0% to 83.3%, and 6 patients discontinued the study. A decreasing trend was observed in the Burton grade. Noninflammatory lesion counts improved in seven patients but increased in four. Sadick noted that these results paled in comparison to the effectiveness of the blue and red combination at lowering inflammatory lesions seen previously, but encouraged the study of the combination phototherapy in a much larger population (J. Cosmet. Laser Ther. 2009;11:125-8).

Several recent reviews have found that red light–activated MAL-PDT, the combination of blue and red light, and aminolevulinic acid as a photosensitizing agent before treatment with blue light, red light, or the 595-nm pulsed dye laser are among the most promising evidence-based laser- and light-based therapies for acne (Semin. Cutan. Med. Surg. 2008;27:207-11; J. Eur. Acad. Dermatol. Venereol. 2008;22:267-78; Dermatol. Surg. 2007;33:1005-26).

In a systematic literature review of randomized controlled trials of light and laser therapies for acne vulgaris (using the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, PsycINFO, LILACS, ISI Science Citation Index, and Dissertation Abstracts International), Hamilton et al. found that trials of blue light, blue-red light, and infrared radiation were more successful, especially when multiple treatments were used. Notably, blue-red light demonstrated better short-term effectiveness than did topical 5% benzoyl peroxide cream (Br. J. Dermatol. 2009;160:1273-85).

Kim and Armstrong have noted that blue light has been demonstrated to photoinactivate P. acnes, but it does not penetrate deeply into the skin. It is believed to work synergistically, however, with red light, which is less effective than blue light at exciting porphyrins but can reach deeper sebaceous glands and may impart an anti-inflammatory effect by inciting cytokine release from macrophages (Dermatol. Surg. 2007;33:1005-26). Indeed, Kim and Armstrong found that combined blue-red light therapy was more effective at lowering the number of inflammatory acne lesions than were benzoyl peroxide monotherapy and blue light monotherapy (Lasers Surg. Med. 1989;9:497-505).

Conclusions

A lengthy review of the literature and personal experience treating patients have convinced me that blue light is an effective treatment for acne. P. acnes is most susceptible to the blue light wavelengths of 407-420 nm. Addition of red light may help speed resolution of inflammatory lesions through an anti-inflammatory effect. Blue and red light devices are efficacious when used in the office if the devices deliver enough joules.

Many at-home devices and iPhone apps have hit the market. These are a great alternative to irritating topicals and antibiotics, and they may help increase compliance. However, many at-home light devices are too weak (do not emit enough joules), or emit a broad range of light (rather than 407-420 nm). The manufacturers of some of these products claim that the heat produced by the devices improves acne, but there is a paucity of research proving this point. In my opinion, using an at-home device twice a day that delivers 407-420 nm (with or without the addition of red light), and delivers enough joules (at least 25 J/cm²), is an effective method of treating acne. For comparison purposes, the in-office Omnilux delivers around 49 J/cm² but is used only two or three times per week. Know your wavelengths and joules when trying to decide which device to sell in your practice or recommend to patients.

Several light devices based on red light–emitting diodes (LEDs) have made their way to the market in recent years. Although red light is not truly a cosmeceutical, it is a significant emerging adjuvant therapy that, like blue light, has been studied in comparison to and in conjunction with topical options primarily to treat acne. Of course, acne is the most common skin disorder prompting visits to the dermatologist, with an estimated 85% of adolescents affected, many into adulthood (J. Am. Acad. Dermatol. 2008;58:56-9).

This discussion will consider red light when used alone and when used in combination with blue light. Blue light is the most effective light to target Propionibacterium acnes (specifically at wavelengths of 407-420 nm). However, many devices are utilizing red light because it has a purported anti-inflammatory effect and penetrates deeper into the skin (Dermatol. Ther. 2005;18:253-66).

Erythrasma

Darras-Vercambre et al. evaluated the effects of red light for the treatment of erythrasma (a superficial skin infection provoked by Corynebacterium minutissimum) in 13 patients. One treatment (80 J/cm²) by red light (broadband, peak at 635 nm) without exogenous photosensitizing molecules was administered to each subject. Therapy was effective and well tolerated, with three patients experiencing complete recovery, and significant reduction of lesions in most other cases. The authors noted that the key to their study, given the absence of an exogenous photosensitizing agent, was capitalizing on the presence of porphyrins in the lesions. They concluded that the use of red light alone for this localized infection is easy and inexpensive, but that an optimal method has not yet been established (Photodermatol. Photoimmunol. Photomed. 2006;22:153-6).

Acne

In 2007, Na and Suh evaluated the efficacy of red light phototherapy with a portable device in 28 volunteers with mild to moderate acne in a split-face randomized trial. Phototherapy was performed twice daily for 15 minutes for a total of 8 weeks to one side of the face. The investigators concluded that red light phototherapy alone is an effective therapeutic option for acne, as they noted significant reductions in noninflammatory and inflammatory lesion counts on the treated side versus the untreated side, a drop from 3.9 to 1.9 in the visual analog scale on the treatment side, and significant disparities between the treatment and control sides after 8 weeks (Dermatol. Surg. 2007;33:1228-33, discussion 1233).

A 2006 article in the British Journal of Dermatology reported good clinical results from acne treatment with photodynamic therapy (PDT) using methyl aminolevulinate (MAL) and red light, but there were adverse side effects that prompted 7 of 19 subjects to discontinue the study (Br. J. Dermatol. 2006;154:969-76). In response to the study, Mavilia et al. wrote a letter to the journal acknowledging their more effective combination therapy using a lower concentration of MAL and low doses of red light. All 16 patients completed the study, in which the count of inflammatory lesions fell an average of 66% with mild but tolerable side effects, including a subtle sensation of heat, then minimal erythema during the procedure and slight scaling that began 3 days after treatment (Br. J. Dermatol. 2007;157:810-1).

In a small study of patients with moderate facial acne, Zane et al. exposed 15 women to 20 J/cm² of broadband red light (600-750 nm) twice weekly for 4 weeks. They also measured skin sebum, pH, hydration, and transepidermal water loss (TEWL). Untreated lesions of the trunk served as controls. The investigators found the treatment safe, well tolerated, and effective, with significant improvement in acne lesions and reduction of sebum excretion and TEWL after 4 weeks of therapy and at the 3-month follow-up visit. They speculated that the improvement was due to the decreased colonization of P. acnes, decimated by photoactivated endogenous porphyrin, and concluded that this inexpensive therapy warrants inclusion among treatment options for moderate acne (Photodermatol. Photoimmunol. Photomed. 2008;24:244-8).

In a 2009 study of 19 patients with moderate to severe facial acne who received a single treatment of low-dose, red-light PDT on the left cheek and MAL 3 hours before red light on the right cheek, both therapies yielded significant reductions in acne score. Red light was found to be as effective as MAL-PDT (Acta Derm. Venereol. 2009;89:372-8).

Combined Blue and Red Light Phototherapy

In 2006, Goldberg and Russell evaluated the combination of blue (415 nm) and red (633 nm) LED phototherapy in 24 patients with Fitzpatrick skin types II-V and mild to severe symmetric facial acne. Twenty-two patients completed the trial, which included two sessions per week (separated by 3 days) alternating between blue and red light for a total of eight sessions. Mild microdermabrasion was used at the start of each session. The mean decrease in lesion count was significant after 4 weeks (46%) and 12 weeks (81%). Inflammatory lesions responded better than did noninflammatory ones, and severe acne responded slightly better than mild acne. The investigators concluded that the combination of blue and red LED phototherapy is free of side effects and pain, and exhibits great potential for the treatment of mild to severe acne (J. Cosmet. Laser Ther. 2006;8:71-5).

In 2007, Lee et al. set out to examine the efficacy of combining blue and red LED phototherapy for acne in a study of 24 patients with mild to moderately severe facial acne. Twice weekly for 4 weeks, patients were treated with quasi-monochromatic LED devices, alternating blue (415 nm) and red (633 nm) light. Fourteen patients self-reported improvements in skin tone and texture. Improvements in noninflammatory and inflammatory lesions were substantial (34.28% and 77.93%, respectively). The researchers concluded that combined blue and red LED phototherapy is a safe and effective option, especially for papulopustular acne (Lasers Surg. Med. 2007;39:180-8).

In 2009, Sadick evaluated the efficacy of the combination of blue (415 nm) and near-infrared (830 nm) LED therapy for moderate acne in 13 females and 4 males ranging in skin type from II to VI and in Burton acne grade at baseline from 1 to 5. Twice-weekly 20-minute sessions were conducted for 4 weeks, alternating between blue and near-infrared light. Eleven patients exhibited improvement ranging from 0% to 83.3%, and 6 patients discontinued the study. A decreasing trend was observed in the Burton grade. Noninflammatory lesion counts improved in seven patients but increased in four. Sadick noted that these results paled in comparison to the effectiveness of the blue and red combination at lowering inflammatory lesions seen previously, but encouraged the study of the combination phototherapy in a much larger population (J. Cosmet. Laser Ther. 2009;11:125-8).

Several recent reviews have found that red light–activated MAL-PDT, the combination of blue and red light, and aminolevulinic acid as a photosensitizing agent before treatment with blue light, red light, or the 595-nm pulsed dye laser are among the most promising evidence-based laser- and light-based therapies for acne (Semin. Cutan. Med. Surg. 2008;27:207-11; J. Eur. Acad. Dermatol. Venereol. 2008;22:267-78; Dermatol. Surg. 2007;33:1005-26).

In a systematic literature review of randomized controlled trials of light and laser therapies for acne vulgaris (using the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, PsycINFO, LILACS, ISI Science Citation Index, and Dissertation Abstracts International), Hamilton et al. found that trials of blue light, blue-red light, and infrared radiation were more successful, especially when multiple treatments were used. Notably, blue-red light demonstrated better short-term effectiveness than did topical 5% benzoyl peroxide cream (Br. J. Dermatol. 2009;160:1273-85).

Kim and Armstrong have noted that blue light has been demonstrated to photoinactivate P. acnes, but it does not penetrate deeply into the skin. It is believed to work synergistically, however, with red light, which is less effective than blue light at exciting porphyrins but can reach deeper sebaceous glands and may impart an anti-inflammatory effect by inciting cytokine release from macrophages (Dermatol. Surg. 2007;33:1005-26). Indeed, Kim and Armstrong found that combined blue-red light therapy was more effective at lowering the number of inflammatory acne lesions than were benzoyl peroxide monotherapy and blue light monotherapy (Lasers Surg. Med. 1989;9:497-505).

Conclusions

A lengthy review of the literature and personal experience treating patients have convinced me that blue light is an effective treatment for acne. P. acnes is most susceptible to the blue light wavelengths of 407-420 nm. Addition of red light may help speed resolution of inflammatory lesions through an anti-inflammatory effect. Blue and red light devices are efficacious when used in the office if the devices deliver enough joules.

Many at-home devices and iPhone apps have hit the market. These are a great alternative to irritating topicals and antibiotics, and they may help increase compliance. However, many at-home light devices are too weak (do not emit enough joules), or emit a broad range of light (rather than 407-420 nm). The manufacturers of some of these products claim that the heat produced by the devices improves acne, but there is a paucity of research proving this point. In my opinion, using an at-home device twice a day that delivers 407-420 nm (with or without the addition of red light), and delivers enough joules (at least 25 J/cm²), is an effective method of treating acne. For comparison purposes, the in-office Omnilux delivers around 49 J/cm² but is used only two or three times per week. Know your wavelengths and joules when trying to decide which device to sell in your practice or recommend to patients.