ALA-PDT and blue light therapy for hidradenitis suppurativa

Journal of Drugs in Dermatology, Jan-Feb, 2004 by Michael H. Gold, Tancy M. Bridges, Virginia Lee Bradshaw, Molly Boring

Abstract

Background: Hidradenitis suppurativa (HS) is a chronic, often suppurative skin condition which affects primarily apocrine glands. A variety of therapies have been used to treat HS, often with unsatisfactory results. Photodynamic therapy (PDT), utilizing topical 20% 5-aminolevulinic acid (ALA) is being used to treat a variety of dermatologic skin concerns, including photorejuvenation and associated actinic keratoses, and acne vulgaris, and other skin tumors.

Objective: The purpose of these case reports is to evaluate the effectiveness of ALA-PDT in treating recalcitrant cases of HS.

Methods: Four patients, not responding to standard HS therapy, underwent short-contact ALA-PDT therapy utilizing a blue light for activation. One to two week intervals between therapies was utilized for 3-4 total treatments and follow-up was for 3 months following the last treatment.

Results: All four of the patients tolerated the therapies well. Clinical improvements from 75-100% were noted n ll of the patients. No adverse effects were seen during the treatments. The treatments were pain free and there was no downtime associated with these ALA-PDT treatments.

Conclusions: HS is a chronic disease which most dermatologists find difficult to treat. The use of ALA-PDT is finding an ever-expanding role in dermatology. These case studies support the use of ALA-PDT in cases of HS. Although all advertising material is expected to conform to ethical and medical standards, inclusion in this publication does not constitute a guarantee or endorsement by the Journal or its staff of the quality or value of such products or of the claims of any manufacturer.

KEYWORDS:

PHOTODYNAMIC THERAPY

HIDRADENTIS SUPPERATIVA

AMINOLEVULINIC ACID

APOCRINE GLANDS

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Introduction

Hidradenitis suppurativa (HS) is a chronic, often suppurative cicatricial skin condition which principally affects apocrine gland-bearing skin. (1, 2) The skin of the axillae and inguinal areas are most commonly involved in those that suffer from HS; reports from other apocrine gland areas are also found including the mammary and perianal areas, buttocks, scrotum, and mons pubis. The etiology of HS includes keratinous plugging of the apocrine duct, dilation of the apocrine duct, and severe inflammation of the apocrine gland. (3) A genetic predisposition may play an important role and hormonal influences may be required for the progression of HS. An association with acne vulgaris exists, although some with HS show no signs of acne vulgaris. (4) A variety of treatments have been reported for HS, often with mixed results. These have included both topical and oral antibiotics; a variety of hormonal therapeutics; intralesional corticosteroids; oral retinoids; and a variety of surgical modalities including incision and drainage, wide surgical excision, and C[O.sub.2] laser therapies have been used. (5)

Photodynamic therapy (PDT) refers to the therapeutic use of photochemical reactions. It involves the use of photosensitizing drugs, the application of an appropriate light source to activate the sensitizing drug which leads to the production of singlet oxygen for tissue destruction. The most common photosensitizing drug used for PDT is 20% 5-aminolevulinic acid (ALA). (6, 7) The combination of ALA-PDT is currently FDA approved for the treatment of non-hyperkeratotic actinic keratoses of the face and scalp. (8) Other dermatologic indications for ALA-PDT include basal cell carcinomas, squamous cell carcinomas, Bowen's disease, actinic chelitis, cutaneous T-cell lymphoma, Kaposi's sarcoma, verrucae vulgaris, and molluscum contagiosum. (6, 7) Recently, this author and investigators have described the successful use of

ALA-PDT in treating acne vulgaris and success with the use of the intense pulsed light source and vascular lasers in the photorejuvenation process and associated actinic keratoses. (9, 10)

PDT works by having diseased tissue produce and accumulate protoporphyrin IX (PpIX). PpIX is a potent photosensitizer and has been shown to accumulate in dysplastic and neoplastic dermatologic skin lesions and epidermal appendages and hair follicles which can be induced by the topical application of 5-ALA HCL, the biological precursor of porphyrin. The exogenously induced photosensitization targets the tissue for PDT. During PDT, the porphyrin molecule itself is photoactivated by exposure to visible light which will result in the production of a cytotic oxygen product that will destroy abnormal cells where the PpIX has been concentrated. There is minimal damage to the surrounding unaffected skin making PDT an attractive therapy for dermatologic concerns. (6, 7)

With this background, we identified four individuals with chronic HS who had not responded to traditional therapy with a variety of topical and systemic agents, as well as intralesional corticosteroid therapy. These patients elected to use ALA-PDT therapy as a last resort prior to contemplating a major surgical procedure or C[O.sub.2] laser therapy. All of the patients tolerated the treatments well. There were no adverse effects noted during these treatments. These therapies were pain-free and not associated with any downtime for these patients.