Photodynamic therapy for the treatment of acne: a pilot study

Journal of Drugs in Dermatology, Nov-Dec, 2004 by Amy Forman Taub

Abstract

Photodynamic therapy (PDT) with use of topical 5-aminolevulinic acid (ALA, Levulan[R] Kerastick[R], Dusa Pharmaceuticals, Inc., Wilmington, MA) photosensitizing agent is a new modality for the treatment of acne. Eighteen patients (aged 15 to 63) with moderate to severe inflammatory acne received ALA-PDT. ALA remained in contact with skin for 15 to 30 minutes before exposure to blue light (ClearLight[TM] [Lumenis] or BLU-U[R] [Dusa Pharmaceuticals, Inc.]) or the Aurora DSR[TM] (Syneron Medical Ltd.), which uses Electro-Optical Synergy (ELOS[TM]), a unique combination of optical and radiofrequency (RF) energy. Patients received two to four ALA-PDT treatments over four to eight weeks or two cycles of ALA-PDT (weeks 2, 4) preceded by salicylic acid peel (weeks 1,3) over four weeks. The average follow-up time was four months. On a scale of 0.0 to 4.0, the average acne grade improvement was 1.75. Among the 12 patients who said their acne had improved, 11 had at least 50% improvement and five had more than 75% improvement. Adverse effects were limited to erythema and peeling for up to five days after treatment and one episode of impetiginization of the affected area. Patients with moderate to severe acne can achieve durable improvement with short-contact ALA-PDT.

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Introduction

Photodynamic therapy (PDT) is a new treatment for acne that involves the topical application of 20% 5-aminolevulinic acid (ALA [Levulan[R] Kerastick[R]]) to the affected area and irradiation with light or laser. ALA is absorbed preferentially by the sebaceous gland, where it is metabolized to protoporphyrins (primarily protoporphyrin IX [PpIX]), that absorb significant amounts of blue, red, and yellow light. Subsequent irradiation leads to photodestruction of Proprionibacterium Acnes (P. Acnes) as well as shrinkage or destruction of sebaceous glands, potentially leading to long-term therapeutic efficacy (1,2).

With maximum absorption at 410 nm (blue) and smaller peaks at 505, 540, 580, and 630 nm, PpIX has been activated by a variety of lasers and light sources (3) in the PDT treatment of acne.

The use of blue light activation in PDT is well established (4). The Aurora DSR[TM] (Syneron Medical Ltd.) uses Electro-Optical Synergy (ELOS[TM]), a unique combination of optical (580-1000 nm) and RF energy (5,6). The purpose of this study was to obtain preliminary data on the efficacy and safety of using blue light, ELOS, and combinations of these light sources to activate photosensitizer in the PDT for acne.

Materials and Methods

Eighteen patients (13 women, 5 men) with moderate to severe inflammatory acne were given ALA-PDT without anesthesia or cooling. Patients (Fitzpatrick skin types 1-3) were aged 15 to 63 years (mean 35), had failed conventional therapy for acne, were willing to undergo PDT, and had no additional cutaneous or non-cutaneous co-morbidities. The average duration of acne was 12 years. Eight patients had taken isotretinoin and 15 had taken oral antibiotics. Patients were excluded if they were pregnant, receiving isotretinoin, or unwilling to avoid sunlight for 48 hours after PDT. All patients gave informed consent to treatment.

ALA was not only applied to individual acne lesions but to the entire affected area. The skin was prepared by performing an acetone scrub and an alcohol scrub. ALA remained in contact with skin for 15 to 30 minutes before irradiation. ALA was removed with acetone and alcohol. Photosensitizer was activated by one or both of the following: 417- to 420-nm blue light (ClearLight[TM] [Lumenis] or BLU-U[R] [Dusa Pharmaceuticals, Inc.]) or the Aurora SR[TM].

Patients were exposed to blue light (BLU-U or ClearLight) for 3 to 7 minutes, one short pass of pulsed light ELOS (18-25 joules/[cm.sup.2] and 18-20 joules/[cm.sup.3] of RF energy).

[FIGURE 1 OMITTED]

Improvement was graded on a scale of 0.0 to 4.0 (0 = no improvement, 4.0 = 100% improvement).

Patients received two to four ALA-PDT treatments over four to eight weeks or two cycles of ALA-PDT (week 2,4) preceded by salicylic acid peel (weeks 1,3) over four weeks. A total of 51 treatments were given. Patients were followed for up to 1 year after the final treatment. Results were evaluated visually by examining photographs taken before and after treatment. Progress was evaluated at 1, 3, 6, and 12 months after the final treatment. Not all patients were available for each scheduled follow-up visit.

Results

Twelve of the 18 patients said their acne had improved with the treatment (Table 1). The average acne grade improvement was 1.75. Eleven of these patients had at least 50% improvement and 5 had more than 75% improvement. Five patients did not improve and flares occurred in two of these five.

Acne lesions have not recurred in one patient and 2 patients have had more than 12 months free of acne. Two more have achieved remission for more than six months. The average follow-up was four months. Two of the 11 patients who did well initially experienced a recurrence at one and two months respectively.