Amyloid deposition after psoriasis therapy with psoralen and long-wave ultraviolet light.

Histologic examination of skin from 52 patients under continued treatment with methoxsalen and long-wave ultraviolet irradiation (PUVA) disclosed small superficial dermal deposits in six subjects who had completed one year of therapy and in six subjects who had completed two years of therapy. These deposits, by light and electron microscopic criteria, are similar to those of lichen amyloidosus. Amyloid deposition should be regarded as a possible complication of PUVA therapy.