Influence of the quantity of sunscreen applied on the ability to protect against ultraviolet‐induced polymorphous light eruption

摘要: Summary Background/Purpose Despite the fact that most people apply less sunscreen than 2 mg/cm2 required to measure sun protection factor (SPF), there is a lack of clinical data on afforded from lower applied quantities. The aim this study was compare ability sunscreens protect against UV-induced polymorphous light eruption (PLE) when at and 1 mg/cm2. Methods Two SPF 45 (one with high level one low UVA protection) were 1 mg/cm2 four randomized 6 × 6 cm areas upper thorax 15 female patients typical history PLE. exposed daily increasing UVA–UVB radiation until PLE reaction detected or maximum five consecutive days. Results The proportion who developed UVA-protection significantly (0%) (73%) both (P = 0.004). At 1 mg/cm2, 33% 80% presented sunscreen, respectively (P = 0.064). Conclusion A broad spectrum able majority development even 1 mg/cm2.