Treatment of Darier's disease with photodynamic therapy.

BACKGROUND: Photodynamic therapy (PDT) using topical 5-aminolaevulinic acid (5-ALA) as a photosensitizer has been reported in the treatment of both neoplastic and benign cutaneous disorders.

OBJECTIVES: To evaluate the efficacy of photodynamic therapy in selected patients with Darier's disease (keratosis follicularis).

METHODS: Six patients with Darier's disease were assessed before and after treatment with PDT using 5-ALA and mean fluence rates of 110-150 mW cm-2.

RESULTS: Of the six patients, one was unable to tolerate the treatment. Of the remaining five, all experienced an initial inflammatory response that lasted two to three weeks. In four of the five patients, this was followed by sustained clearance or improvement over a followup period of six months to three years. Three of these four patients were on systemic retinoids and the fourth had discontinued acitretin prior to PDT. In the fifth patient partial improvement was followed by recurrence after etretinate therapy was discontinued. Biopsy specimens taken immediately after the procedure in two patients demonstrated a mild inflammatory cell infiltrate in the dermis. A biopsy obtained eighteen months after PDT from a successfully treated area showed no signs of Darier's disease and a subtle increase of collagen in the upper dermis.

CONCLUSIONS: Photodynamic therapy can be viewed as a potential adjunctive modality for Darier's disease but should not be considered as a substitute for retinoids in patients who require systemic treatment.