Unusual Types of Cyst: Eruptive Vellus Hair
Eruptive vellus hair cysts appear as multiple, maybe even hundreds of 1-4mm skin-colored or hyper-pigmented dome-shaped papules (raised and swollen areas) on the mid-chest and upper extremities. Vellus hairs are short, fine hairs that line our skin making these cysts common. They tend to be smaller than steatocystomas and can have a central area of umbilication (dimpled center). Steatocystoma may at times have vellus hairs, and Eruptive Vellus Hair Cysts may have sebaceous glands (oil glands) in their lining, which leads some dermatologists to believe these two conditions may be related. Treatment is gentle extraction. There is a high chance of recurrence if a carbon dioxide laser is used to extract them, and topical retinoid tazarotene has also been used, but is considered inferior treatment.