[Appearance of disseminated hyperpigmented lesions during PUVA therapy]

Disseminated, hyperpigmented lesions were observed in two patients with psoriasis under PUVA treatment independently from psoriatic lesions. Light microscopic examination revealed besides hypertrophy of melanocytes no considerable changes. Additionally to the formation of large melanosomes (Longitudinal diameter over 8,8 micrometers) and the pronounced melanin-storage in the melanophages, electron microscopic results referred to degenerative processes of melanocytes and the epidermal basal lamina.