Porokeratotic eccrine duct and hair follicle nevus (PEHFN) associated with keratitis-ichthyosis-deafness (KID) syndrome.

Porokeratotic eccrine ostial and dermal duct nevus is a rare hamartomatous malformation, histologically characterized by cornoid lamellae overlying dilated eccrine ostia. The nevus most commonly presents in the form of multiple filiform keratotic spines in a linear arrangement, usually on the distal extremities. Porokeratotic eccrine and hair follicle nevus is thought to be a variant of porokeratotic eccrine ostial and dermal duct nevus that additionally involves hair follicle infundibula.