A HIGH SPF SUNSCREENS EFFECTS ON UVB-INDUCED IMMUNOSUPPRESSION OF DNCB CONTACT HYPERSENSITIVITY

Several studies in mice of the protection afforded by sunscreens from UVB-induced suppression of contact hypersensitivity have yielded confl icting reports ranging from complete protection to no protection. Firs tly, we sought to determine the effects of sunscreen and UVB on Langer hans cells; secondly we sought to determine whether the effect of prea pplication of sunscreen with a sun protection factor of 30 could preve nt local UVB-induced suppression of contact hypersensitivity to dinitr ochlorobenzene in humans. In the first part of the study we compared a control group with a sunscreen plus UVB group and enumerated the numb er of Langerhans cells in each group. In the second part of the study we had four groups: a control group, a UVB group, a sunscreen group, a nd a sunscreen plus UVB group. Our results show that application of a sunscreen prior to UVB can prevent the decrease in number of Langerhan s cells in an irradiated site. In the second part of the study, our re sults indicate that sunscreen, in itself, does not interfere with cont act hypersensitivity, and that a high SPF sunscreen applied prior to U VB irradiation partially prevents suppression of contact hypersensitiv ity. (C) 1997 Elsevier Science Ireland Ltd.