Twenty-five patients have been observed with a uniform eruption consisting of discrete keratotic follicular papules distributed mainly over the extremities. Histologically each lesion represents a dilated hair follicle plugged with keratinous material and masses of necrotic crust. The follicular epithelium shows single or multiple areas of perforation into the corium. For this eruption, we propose the name of "perforating folliculitis."
Mehregan AH, Coskey RJ. Perforating Folliculitis. Arch Dermatol. 1968;97(4):394-399. doi:10.1001/archderm.1968.01610100034004