Possible ultraviolet A-induced lentigines: a side effect of chronic tanning salon usage.

A patient who developed lentigines after prolonged ultraviolet A (UVA) exposure in a tanning booth is described. The patient had no exposure to psoralens or furocoumarins. Histologic examination of a representative lentigo revealed melanocytic hyperplasia and cytologic atypia. Increased nevocytic activity with histologic dysplasia was present in several junctional nevi excised during the period of UVA exposure. Several studies have revealed significant effects of UVA on melanocytes. Patients should be cautioned to avoid tanning bed use in view of these potentially deleterious effects.