Woronoff's rings with PUVA therapy.

A perilesional pale ring of skin that was seen during ultraviolet (UV) treatment of psoriatics was described by Woronoff in 1926.1Recent studies into the pathogenesis of Woronoff's ring (WR) phenomenon were conducted by Penneys et al2during coaltar and UV-light treatment of psoriatics. A phenomenon similar to the Woronoff's rings (WR) was observed by us in a patient who was undergoing Psoralen and UVA (PUVA) therapy for psoriasis and this study was conducted to determine the frequency of WR in PUVA-treated psoriatics. Patients and Methods Twenty patients with psoriasis vulgaris were examined before and during PUVA treatment. The regimen followed that of Parrish et al in 1974.3Patients took methoxsalen capsules orally (0.6 mg/kg of body weight) two hours before treatment with long wavelength UV light irradiation. The lamps used were of two types—one with 48 and the other with 36 vertical lamp tubes. Each contained