Tufts in the tunnels: A dermoscopic and microscopic insight into trichostasis spinulosa

A 62-year-old woman presented with multiple asymptomatic, comedo-like black papular lesions localized to the nose, gradually increasing in number over several years. The lesions were spiny, non-inflammatory, and predominantly clustered over the nasal tip and alae [Figure 1]. Family history was unremarkable, with no similar lesions reported among first-degree relatives. Polarized dermoscopy revealed multiple tufts of short, dark vellus hairs emerging from dilated follicular openings, each surrounded by a faintly pigmented perifollicular halo [Figure 2]. Gentle extraction of a follicular plug followed by light microscopy demonstrated a compact cluster of 10–20 fine vellus hairs encased within a keratinous sheath, consistent with a diagnosis of trichostasis spinulosa (TS) [Figure 3].

Close

Figure 1:

Clinical image showing multiple black follicular papules on the nose.

Export to PPT

Close

Figure 2:

Dermoscopy revealing tufts of dark short hairs arising from dilated follicular openings on the nose (Heine DELTAone, polarized, 10x).

Export to PPT

Close

Figure 3:

Microscopy showing multiple vellus hairs tightly packed together, extracted from a single follicular opening (KOH mount, 400x).

Export to PPT

TS is a commonly underdiagnosed follicular disorder caused by the retention of multiple vellus hairs within dilated follicles. TS should be considered in the differential diagnosis of black follicular papules, particularly in older adults with photodamaged skin.^[1] Dermoscopy is a valuable, non-invasive tool for diagnosis, and microscopy confirms the characteristic tuft of vellus telogen club hair, aiding in definitive identification. Dermoscopic characteristic features include tufts of short vellus hairs emerging from a single follicular ostium, producing a “paintbrush” or “spike cluster” appearance, often surrounded by a pigmented halo.^[1,2] Microscopic examination confirms the diagnosis by demonstrating bundles of telogen club hairs within a keratinous matrix. Recognizing these features can help avoid misdiagnosis as open comedones and allows for targeted treatment using keratolytics, topical retinoids, or manual extraction. Recurrence is common, and long-term cosmetic management may be required.^[1,2]