Eruptive vellus hair cysts

Eruptive vellus hair cysts (EVHC) is an uncommon condition, characterised by occlusion and cystic dilatation of vellus hair follicles, and presenting in children and young adults with multiple red-brown or blue-grey monomorphic papules, most commonly affecting the central chest.

This chapter is set out as follows:

• The cause is unknown
• Cases can be sporadic or familial
• In some familial cases, the condition can coexist with steatocystoma multiplex

• EVHC is likely to be familial if it arises in early childhood. Sporadic forms may appear at any age, although they show a clear trend towards occurring during the first three decades of life
• Boys and girls are equally affected
• The conditions is asymptomatic

• EVHC presents as small, red-brown or blue-grey papules, most commonly on the central chest, although other sites can be affected, and occasionally it can be generalised
• There may be just a few cysts, or, often, there may have several hundred 

• Twenty-five percent of EVHC cases resolve spontaneously

• Topical retinoids and emollients containing urea have been reported as effective in some cases

• Although physical treatments such as dermabrasion, cryotherapy, curettage, and laser therapy have all been reported as benefiting some patients, lesions can be recurrent, and such treatments can in the long-term make matters alot worse if they result in hypertrophic or keloid scarring of the chest