Treatment of moderate to severe inflammatory acne vulgaris: photodynamic therapy with 5-aminolevulinic acid and a novel Advanced Fluorescence Technology pulsed light source

Journal of Drugs in Dermatology, March, 2007 by Michael H. Gold, Julie A. Biron, Molly Boring, Tancy M. Bridges, Virginia L. Bradshaw

Abstract

The use of photodynamic therapy (PDT) with 20% 5-aminolevulinic acid (ALA) for the treatment of acne vulgaris has been explored. This study evaluates the safety and efficacy of a new Advanced Fluorescence Technology (AFT) pulsed light source (420-950 nm) for photoactivation in ALA PDT for the treatment of moderate to severe inflammatory facial acne vulgaris. Nineteen subjects received 4 ALA PDT treatments with the AFT pulsed light source. Treatments were spaced 2 weeks apart. ALA was incubated for 15 to 30 minutes. At the end of the fourth treatment, the total reductions in inflammatory and noninflammatory lesion counts were 54.5% and 37.5%, respectively. Median Global Severity Scores suggest a trend toward reduction after several treatments. Investigator and subject assessments show moderate to marked improvement in most patients. The new AFT pulsed light source with ALA PDT appears to be a safe and effective modality for the treatment of moderate to severe inflammatory acne vulgaris.

Introduction

The use of photodynamic therapy (PDT) with 20% 5-aminolevulinic acid (ALA) for the treatment of mild to severe acne vulgaris has been explored by many investigators. The rationale for this approach is based on the update of exogenous ALA by pilosebaceous units, the conversion of ALA to photosensitive protoporphyrin IX (PpIX), the production of porphyrins by Propionibacterium acnes, and the photoexitation of PpIX and bacterial porphyrins to form cytotoxic singlet oxygen. A variety of light sources and lasers have been used for photoactivation of ALA-induced PpIX (1-3) and methyl aminolevulinate (MAL) has also been used as photosensitizing agent. (4) A panel of experts has recently agreed that ALA PDT is generally more effective against inflammatory and cystic acne than comedonal acne. (3)

This study evaluates the safety and efficacy of a new pulsed light source (420-950 nm) with Advanced Fluorescent Technology (AFT) for photoactivation in ALA PDT for the treatment of moderate to severe inflammatory acne vulgaris of the face.

Materials and Methods

Nineteen healthy subjects (aged 19 to 46 years, skin types II-VI, all women) with moderate to severe inflammatory acne of the face (at least 20 inflammatory lesions and a Global Severity Score of 2) participated in the study. The study was approved by the Essex Institutional Review Board, Inc., and all subjects gave signed informed consent to treatment. Subjects were excluded if their histories included previous treatment with laser or light devices or ALA to areas to be treated, severe comedonal acne, autoimmune disease, porphyria or allergy to porphyrins, abnormal photosensitivity, mental illness, topical acne medications within the previous 2 weeks, systemic antibiotics or steroids within the previous 4 weeks, systemic retinoids within the previous 6 months, treatment with an investigational drug within the previous 30 days, dermal filler treatments, botulinum toxin, chemical peels, dermabrasion, keloid or scar formation, uncorrected coagulation defects, or any condition which, in the investigator's opinion, would make it unsafe to participate in this study. Pregnancy or unacceptable methods of birth control were also grounds for exclusion.

At the beginning of the study subjects were given a cleanser to use throughout the study and beginning at least 7 days prior to the first study medication application. Subjects were instructed to avoid other cleansers or prohibited topical medications other than the study medications on their face.

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The study flow chart is shown in Table 1. Patients received 4 ALA PDT treatments with the AFT pulsed light source (420-950 nm, Harmony, Alma Lasers, Inc., Fort Lauderdale, Fla). The ALA was Levulan[R] Kerastick[R] (Dusa Pharmaceuticals, Wilmington, Mass). Treatments were spaced 2 weeks apart. ALA incubation times varied from 15 to 30 minutes. Fluences were 5 to 7 J/[cm.sup.2], pulse width was 30 to 50 ms, and light treatment was for 5 to 10 minutes. The 420 handpiece was used throughout the study and subjects typically received 2 passes at each treatment session.

Results were evaluated by lesion counts, Global Severity Score, improvement scores, and adverse effects.

Acne lesions were counted on visits 1 through 6. Comedones (open and closed), papules, and pustules, and nodules were counted and recorded on the face vertically from the hairline to mandible rim and horizontally from ear to ear.

A Global Severity Score was assigned to each subject on visits 1 through 6. The scale was 0 to 3 in which 0 = clear, no lesions; 1 = mild, less than 10 inflammatory lesions; 2 = moderate, around 20 inflammatory lesions; and 3 = severe, greater than 40 inflammatory lesions localized or scattered. Enrolled subjects had a Global Severity Score at least 2 at visit 1.

Improvements were assessed by comparing facial acne to observations at visit 1. Improvement grades were assigned as follows: 0 = none; 1 = slight (25%); 2 = moderate (50%); 3 = marked (75%); 4 = complete clearing (95%).