Eruptive vellus hair cyst - Skin in Child
The etiology of EVHCs is unknown, but they are considered to be a developmental anomaly of body hair follicles, where obstruction of the neck of follicular channel leads to cystic dilation of the follicle followed by subsequent retention of vellus hairs and atrophy of the hair bulbs.
EVHCs characteristically present in childhood and adolescence, although cases have been reported in adulthood and in the elderly. Familial cases present at birth or early infancy, whereas sporadic cases tend to develop in the first or second decades of life. No predilection in any ethnicity or either sex has been established.
EVHCs have been associated with steatocystoma multiplex, trichostasis spinulosa, hypohidrotic ectodermal dysplasia, pachyonychia congenita, Lowe syndrome, and chronic renal failure as well as other neurological disorders.
L73.8 – Other specified follicular disorders
254685008 – Eruptive vellus hair cysts
- Acne vulgaris (comedones)
- Steatocystoma multiplex – Different distribution with a predilection for the neck, axillae, and arms.
- Keratosis pilaris
- Pityrosporum folliculitis
- Perforating folliculitis
- Molluscum contagiosum
- Epithelial cysts – Consider Gardner syndrome with multiple epithelial cysts.