Vitiligo following the resolution of psoriatic plaques during PUVA therapy

Abstract

Vitiligo Is an acquired idiopathic disorder, involving 1–4% of tiie world population and characterized by depigmented white patches of the skin that lack the dopa‐positive melanocytes.It has been associated with physicai trauma and, systemic and cutaneous diseases. Among the many dermatoses, psoriasis has been reported to be associated with vitiiigo in the same individuals independently, or vitiligo may precede the formation of psoriasis at the same location. Currently, psoralen plus ultraviolet A iight (PUVA) is one of the efficacious treatments of psoriasis and vitiligo with side‐effects of hypopigmentation and vitiligo‐like lesions. We describe a patient with psoriasis vuigaris in whom vitiligo appeared in the same areas and configurations as his psoriatic plaques as they resolved while being treated with topicai PUVA.A 19‐year‐old Caucasian man was referred for treatment of his psoriatic flare. His medical history revealed a vitiiigo patch on his right calf at age five. At age 14, he developed initially psoriatic plaques on his knees and elbows which then gradually spread to the legs, arms, hands, trunk, scalp, and the genitai area. The only therapy used was a mid‐potency topical steroid ointment with some reiief. Recently the condition had deteriorated enough to seek medical attention.Physical examination revealed sharply demarcated erythematous, silvery‐white scaly papules, patches and plaques of various sizes on trunk, extremities, palms, buttocks, and penis. The patient received topical PUVA with 0.1% trimethoxalen cream for 3 months. Uitravioiet A light (UVA) was applied at 0.1 J/cm with an increment of 0.1 J/cm at each session as tolerated. At approximately the tenth session, depigmented lesions were noted around the margins of the regressing psoriatic plaques. This progressed continually until the vitiligous‐like lesions completely replaced the resolved psoriatic piaques in exactiy the same configurations (Fig. 1).Skin biopsies of the depigmented areas revealed parakeratosis, hypogranulosis, acanthosis, and a sparse iymphocytic infiitrate around dilated tortuous capillaries in the upper corium (Fig. 2). Also a Fontana‐Masson stain showed an absence of melanocytes as may be seen in vitiligo (Fig. 3).