Vellus hair (VH) is sensitive marker of hair re-growth.
Short
vellus hair (SVH) is seen as new, thin and unpigmented hair within the patch.11 The regrowth of SVHs can be a sign of treatment response in dermoscopy even when the recovered hair is hardly perceived by the naked eye.
Our report details two cases of uncommon pilosebaceous tumors, steatocystoma multiplex, and eruptive
vellus hair cysts.
Eruptive Vellus Dermal cysts lined by stratified squamous Hair Cysts epithelium, with granular layer, contained
vellus hairs; no sebaceous glands [6] Epidermoid cysts Cysts lined by stratified epithelium, with granular layer, lamellar keratin inside [7] Milia Small cysts in the superficial dermis coated by epithelium with granular cell layer' contains lamellar keratin [7] Trichilemmal cysts Cysts lined by squamous epithelium without granular layer, filled with homogenous keratin [7] Steatocystomas Cysts lined by stratified squamous epithelium without granular layer and
vellus hairs inside the cavity; sebaceous lobules close to the cystic wall [7]
In patients with alopecia areata the most common trichoscopic feature (Figure 2) was black dots in 12 patients, 60.0%, followed by yellow dots seen in 11 patients, 55.0%, exclamation mark in 11 patients, 55.0%, white hairs in 9 patients, 45.0%, short
vellus hairs in 8 patients, 40.0%, short broken hairs in 8 patients, 40.0%, and pig tail growing hairs in 3 patients, 15.0% (Table 2).
The higher positivity may be due to the fact that diameter of terminal hair of scalp is almost twice that of
vellus hair in other body areas, hence, the total volume of desmosomal structure is greater per unit area of scalp than in any other epidermal site.1,9 It is also statistically proven in our study that DIF on plucked hair is more reliable as compared to DIF on Tzanck smear.
Selected patients will be thoroughly examined for type of hair (Terminal or
vellus hair, density, calibre, i.e.
Eventually, with age, the follicles may degenerate to produce
vellus hair again, or shut down completely.
Black dots were next most common finding, seen in 68.7% of patients, followed by broken hair (59.7%),
vellus hair (49.3%) and tapering hairs (25.4%).
The patient was diagnosed with eruptive
vellus hair cysts (EVHC).