Eruptive vellus hair cysts.

Of 11 patients with eruptive vellus hair cysts, seven were between ages 17 and 24 years when the dermatosis first appeared. The sites of predilection were mainly the anterior part of the chest and the extremities, though the lesions were also seen on the face, neck, axilla, and groin. In some lesions that regressed spontaneously, the cysts were connected to the surface, forming an opening pore. In other lesions, the cystic material formed foreign-body granulomas by degradation of the cyst walls.