Effects of Exposure to Ultraviolet Light in a Commercial Solarium on Langerhans Cells and Melanocytes in Human Epidermis

S ummary Nine subjects of Celtic and mixed European descent were exposed to small (1/2 hour) doses of ultraviolet light (UVL) on 10 consecutive days in a commercial solarium to determine the effects of UVL on epidermal melanocytes and immunocompetent Langerhans cells (LCs). Tanned and non‐tanned subjects were studied to determine whether pigmentation from melanocytes provided the LCs with any protection against these UVL effects. A transient reduction in the number of LCs occurred in response to UVL exposure, returning to near pre‐exposure levels two weeks after cessation of the solarium course. The tan which developed or deepened following the UVL exposure appeared to provide little or no protection against this reduction, regardless of whether the subjects were lightly tanned or untanned prior to the solarium course. Even though the number of subjects examined was small these results indicate that exposure to solarium UVL irradiation, even in small doses, may adversely affect the skin immune system and therefore is not recommended as a safe means of acquiring a tan.