Summertime actinic lichenoid eruption (lichen planus actinicus).

A patient with an unusual lichenoid photosensitive eruption is presented. The features differentiating this entity from classic lichen planus, lupus erythematosus, and polymorphous light eruption are discussed. Phototesting confirmed the provocative influence of sunlight. We prefer the name "summertime actinic lichenoid eruption" to that of "lichen planus subtropicus" or "lichen planus actinicus," since this condition is not confined to subtropical countries, and, although light appears to initiate the eruption, its exact relationship to lichen planus is unclear.