Trichostasis spinulosa is a common yet underdignosed condition affecting hair follicles. It occurs on the face especially the nose. Diagnosis is based on the clinical features, hair mount, and dermoscopy. Rarely, it can present in nevoid distributions, making diagnosis a difficult task.1
A 2-month-old baby was brought with a history of sudden appearance of new hairs on the back since 1 week. On examination, multiple tiny scattered black dots were noted in the interscapular area (Fig. 1). Diffuse erythema was present. Keratosis pilaris (KP) and eruptive vellous hair cysts (VHCs) were considered as differentials. Dermoscopy demonstrated tuft of entangled hairs forming aggregation and emerging from a single follicle with 5 to 15 vellous hairs (Fig. 2) and white dots in regular, equidistant distribution. Dermoscopy of KP shows looped and coiled hairs embedded in epidermis with perifollicular erythema and scaling, whereas nonfollicular, pale blue areas with indistinct borders are noted in eruptive VHC.2-4 In this case, dermoscopy demonstrated tuft of entangled hairs in each follicular opening without peripilar erythema and scaling. White dots represent sweat duct openings. Thus, based on dermoscopic findings, a diagnosis of nevoid TS (NTS) was made. Hence, dermoscopy aids in the diagnosis of NTS as a noninvasive diagnostic procedure.