Multiple benign lichenoid keratoses simulating photodermatoses: evolution from senile lentigines and their spontaneous regression.

Evidence from several studies has established that a solitary benign lichenoid keratosis evolves from a senile lentigo. This lesion tends to resolve spontaneously with partial or complete regression of the original senile lentigo. In a 2-year period we studied fourteen patients with multiple benign lichenoid keratoses simulating photodermatoses. The original two patients were thought initially to have either cutaneous lupus erythematosus or a drug-induced photodermatitis. All fourteen patients were found to have multiple benign lichenoid keratoses distributed primarily in sun-exposed skin and arising from preexisting senile lentigines. The lichenoid lesions disappear either with topical corticosteroid treatment or spontaneously and are followed by partial or complete regression of the original senile lentigines. This disease entity seems to be fairly common and may be easily confused with photodermatoses.