Atrichia With Papular Lesions

Atrichia with papular lesions (APL) is a rare autosomal recessive disorder characterized by irreversible alopecia and keratin cysts, caused by mutations in the Zinc finger domain of the human hairless gene on chromosome 8p12. An 11-year-old male presented with extensive alopecia starting at six months of age and keratotic papules on the face and trunk. Biopsies confirmed the presence of mid-dermal keratin cysts and few vellus follicles without terminal hairs. Accurate diagnosis of APL is crucial to avoid misdiagnosis as alopecia universalis and unnecessary steroid treatments. Vitamin D-dependent rickets, which has a similar clinical presentation, was ruled out.