Trichostasis spinulosa (TS) is a common disorder of follicular hyperkeratosis and associated entrapped multiple tiny vellus hairs.

Although demographics have not been widely studied, it is proposed that this condition affects mostly adults and is relatively rare in children. The condition is proposed to affect men and women in equal ratios and is more common in individuals with dark skin phototypes (Fitzpatrick III or higher). The pathogenesis of TS is unclear.

The most common location cited is the nose; however, TS can be found other places such as on the cheeks, back, anterior trunk, and axillae. TS is usually asymptomatic and therefore is largely considered a cosmetic issue. A pruritic variant exists and is proposed to be more common in younger adult females.

Without treatment, TS will persist and may progressively cover a more extensive area.