Treatment of hypopigmented sarcoidosis with 8-methoxypsoralen and long wave ultraviolet light.

A patient with hypopigmented sarcoidosis involving the face was treated with topical 8-methoxypsoralen and long wave ultraviolet light. Satisfactory repigmentation occurred within eight months of tri-weekly therapy. Electron microscopic study of involved, untreated skin showed abnormalities of melanocytes, including cytoplasmic vacuolization and the presence of melanosome complexes. Treated skin showed sparsity of melanosomes within the central portions of some melanocytes and large numbers of melanosomes within melanocytic dendrites. The clinical and ultrastructural findings suggest the possibility of toxic damage to melanocytes, perhaps with abnormalities of melanosome transfer, in lesions of hypopigmented sarcoidosis. These abnormalities appear to be responsive to psoralen-UVA therapy.