VITILIGO FOLLOWING THE RESOLUTION OF PSORIATIC PLAQUES DURING PUVA THERAPY

Vitiligo is an acquired idiopathic disorder, involving 1-4% of the wor ld population and characterized by depigmented white patches of the sk in that lack the dopa-positive melanocytes.(1) It has been associated with physical trauma and, systemic and cutaneous diseases.(2,3) Among the many dermatoses, psoriasis has been reported to be associated with vitiligo in the same individuals independently,(4) or vitiligo may pr ecede the formation of psoriasis at the same location.(5) Currently, p soralen plus ultraviolet A light (PUVA) is one of the efficacious trea tments of psoriasis acid vitiligo with side-effects of hypopigmentatio n and vitiligo-like lesions.(6) We describe a patient with psoriasis v ulgaris in whom vitiligo appeared in the same areas and configurations as his psoriatic plaques as they resolved while being treated with to pical PUVA. A 19-year-old caucasian man was referred for treatment of his psoriatic Rare. His medical history revealed a vitiligo patch on h is right calf at age five, At age 14, he developed initially psoriatic plaques on his knees and elbows which then gradually spread to the le gs, arms, hands, trunk, scalp, acid the genital area. The only therapy used was a mid-potency topical steroid ointment with some relief. Rec ently the condition had deteriorated enough to seek medical attention. Physical examination revealed sharply demarcated erythematous, silver y-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. Ultraviolet A light ( UVA) was applied at 0.1 J/cm(2) with an increment of 0.1 J/cm(2) at ea ch session as tolerated. At approximately the tenth session, depigment ed lesions were noted around the margins of the regressing psoriatic p laques. This progressed continually until the vitiligous-like lesions completely replaced the resolved psoriatic plaques in exactly the same configurations (Fig. 1). Skin biopsies of the depigmented areas revea led parakeratosis, hypogranulosis, acanthosis, and a sparse lymphocyti c infiltrate around dilated tortuous capillaries in the upper cerium ( Fig. 2), Also a Fontana-Masson stain showed an absence of melanocytes as may be seen in vitiligo (Fig. 3).