Evaluation of the capacity of sunscreens to photoprotect lupus erythematosus patients by employing the photoprovocation test

Although sunscreens are widely used to photoprotect patients with photosens itive Iupus erythematosus (LE), standardized controlled studies that can pr ove their efficacy for this indication have been lacking. Therefore, in the present study, the capacity of three different, commercially available sun screens to prevent the development of skin lesions that have been induced i n LE patients under standardized, reproducible conditions by employing a pr ovocative phototest mas assessed. In a double blind, intraindividual compar ative study, 11 patients with LE mere photoprovoked according to a standard protocol. AU patients developed LE-specific skin lesions upon photoprovoca tion with a combination of UVA plus UVB radiation. Each of the sunscreens t ested prevented the development of skin lesions in this assay, but to vario us extents. Suncreen A (UVB: Octocrylene; UVA: Mexoryl SX, Mexoryl XL, Pars ol 1789; TiO2) was by far the most effective by protecting in 11/11 patient s. This protective capacity was corroborated by studies in which strong ICA M-1 mRNA expression was found in unprotected test areas, but not in sunscre en A pretreated sites. In contrast to sunscreen A, sunscreen B (UVB: Eusole x 6300, Parsol MCX, Uvinul T150, Neohelipan; UVA: Parsol 1789; TiO2) protec ted in 5 patients and sunscreen C (Eusolex 6300, Parsol MCX, Uvinul T150; U VA: Parsol 1789; TiO2) in 3 out of 11 patients. These studies indicate that the use of sunscreens is beneficial to LE patients because it can prevent the development of UV radiation-induced skin lesions. Effective protection, however, might vary considerably between different sunscreens.