Multiple self-healing squamous epithelioma.

Multiple self-healing squamous epithelioma is determined by a rare autosomal allele in heterozygous state and affects both sexes with approximately equal severity. The lesions are found more frequently on exposed areas of skin and their distribution correspondingly differs between the sexes. Reliable information on 62 cases has been obtained in the west of Scotland. This number of patients is more than twice that recorded in the world literature. It seems possible that the Scottish cases have arisen from a single mutation occurring before 1790.