Atrichia with papular lesions (APL) is a rare autosomal recessive form of inherited alopecia. Males and females are equally affected and present with a distinct pattern of total hair loss on scalp, axilla and body. Normal hair is present at birth in most APL patients, which they lose shortly after birth. This form of hair loss is irreversible and the histology is consistent with an absence of mature hair follicles. In addition to total atrichia, APL patients also present with papules and follicular cysts filled with cornified material. Patients are essentially devoid of eyebrows and eyelashes.
Mutations in the hairless (HR) gene are responsible for this condition.