Photodynamic Therapy With Topical 5% 5-Aminolevulinic Acid for the Treatment of Truncal Acne in Asian Patients
June 2016 | Volume 15 | Issue 6 | Original Article | 727 | Copyright © June 2016
Yik Weng Yew MD MPH,a Yi Chun Lai MD MPH,b Yen Loo Lim MD,a Wei-Sheng Chong MD,a and Colin Theng MDa
aNational Skin Centre, Singapore
bHarvard T.H. Chan School of Public Health, Boston, MA
BACKGROUND: Photodynamic therapy (PDT) using topical application of aminolevulinic acid (ALA) is an effective treatment for acne vulgaris. However, there is no clear consensus on the treatment regime in Asians.
AIM: To determine the efficacy, safety and tolerability of 5% ALA PDT in the treatment of truncal acne in Asians.
METHODS: Patients with truncal acne were treated with 5%-ALA under occlusion for 3 hours. All were subsequently treated with a red light source at wavelength 630 nm and an irradiance of 38mW/cm2
giving a total dose of 37 J/cm2
. The numbers of acne lesions were recorded at baseline and regular intervals after treatment together with any adverse effects.
RESULTS: Fifteen patients were recruited. Overall, there was a 64.2% reduction in the inflammatory lesions count and a 24.3% reduction in the non-inflammatory lesions count at the end of the 12 weeks follow-up. Both mean lesions counts were significantly lower than baseline at all follow-up time points with paired t tests (all P values <0.05). Pain was well tolerated among our patients.
CONCLUSION: A single treatment session of 5%-ALA PDT was effective for the treatment of truncal acne with little side effects and acceptable in our Asian patients. J Drugs Dermatol
Acne vulgaris is a common skin condition that can affect the face as well as the trunk among adolescents and young adults.1 It can affect the quality of life of many patients and has long lasting psychological effects.2 Truncal acne can be potentially challenging to treat since self application of topical treatments is not always easy and, in selected cases, there is a lack of efficacy to oral antibiotics because of antibiotic resistance.3 Some patients would require oral isotretinoin as a form of systemic treatment. Photodynamic therapy (PDT) using topical application of 5-aminolevulinic acid (ALA) has been proposed as a new treatment alternative in acne vulgaris. Its mode of action in acne vulgaris is through the killing of Propionibacterium acnes, which is important in the pathogenesis of acne vulgaris. Furthermore, the ALA accumulates in the sebaceous tissues and, when activated, results in a decrease in sebum production. Recent studies have demonstrated that topical ALA photodynamic therapy causes apoptosis of sebaceous glands and down-regulates toll-like receptor (TLR)-2 and TLR-4 expression in the sebaceous glands and epidermis of patients with acne.4
Various studies have shown that it is a safe and effective treatment for acne vulgaris.5-9 Most studies on 20%-ALA PDT in the treatment of acne vulgaris in Caucasian patients with Fitzpatrick skin type I and II showed good efficacy and relatively few adverse effects.5,7,8 However, there has been relatively few published data on the effectiveness of PDT for truncal acne, particularly in Asian patients. It has been reported that there are more severe erythema and post inflammatory hyperpigmentation (PIH) when the usual dose of 20%-ALA PDT is used in the treatment of moderate to severe facial acne in Chinese patients with mostly Fitzpatrick skin type III and IV.10 In this pilot study, we aim to assess the efficacy, safety, and tolerability of a single session of 5%-ALA PDT in the treatment of truncal acne in Asian patients.
The clinical study was conducted at a tertiary outpatient dermatology clinic from March 2008 to December 2010. Patients over the age of 18 years with moderate or severe truncal acne were recruited into the study. Severity of truncal acne was stratified according to a physician global assessment scale of none, mild, moderate and severe. All patients were treated with a single ALA PDT treatment on the target site. All topical and systemic treatments were discontinued for all study participants prior to the study. In addition, there was a 2-week washout period of all oral antibiotics and topical therapies at the treatment sites. Written consent was obtained from all patients and the study protocol was approved by the institute research ethics board.
Topical 5% 5-ALA cream (Sigma Aldrich, USA) was applied to the site and kept under occlusion with a polyurethane dressing