Sunscreen and immunosuppression.

Recently, Walker and Young (1997) reported that ultraviolet (UV) B sunscreens offer the same UVB protection factors against inflammation and immunosuppression in the mouse . The authors studied the relationship between photoprotection of inflammation and immunosuppression with monochromatic (Phi lips TL-01 tubes, A..,. _,= 311mll) UVB radiation. T he UVB dose-response curve for murine edema was similar to that for human erythema . T he protection afforded by the UVB fi lters, octyl dimethyl paraaminobenzoic acid and 2-ethylhexyl-4'-methoxycinnamate (2EHMC), revealed that topical or tape application of sunscreen protected totally agai11st UV-induced inflammation but onJy partiail y against UV-indu ced immunosuppressio n. Furthermore, a sun protection factor (SPF) of 4, i11 vi 11o, was determined for 2-EHMC for both inflammation and immunosuppression. These fu1d ings , however, are confu sing. On the one hand , the investigators used minimally significant increases in skin edema or suppression of contact hypersensitivity (CHS) to de fin e minimal inflammatory (MID) and minimal immunosuppressive doses (MISD) (p < 0.05). In both unprotected and 2-EHMC-protected mice , the MID and MISD w ere th e same and w ere determined to be 773 mj / cm and 3091m]/cm , respectively. On the other hand, the comparison of protective effects of UVB sunscreens showed that 2-EHMC-treated mice exposed to 2.8 MID (2184 mjlcm 2 )