Trichostasis spinulosa (TS) is a relatively common but underdiagnosed disorder of hair follicles that retain successive telogen hairs. It has been described within skin lesions (secondary TS) or as an isolated finding (primary TS). Dermoscopy may help identify the characteristic hair tuft. We report 2 cases of TS.
The first case involved a 23-year-old woman who presented with a long-standing history of a light-brown papule on the lower part of her back. There was a black punctum in the upper central area of the lesion (Figure 1). Dermoscopy showed a sparse pigment network, multiple commalike blood vessels that are typical of intradermal melanocytic nevi, a few peripheral vellous hairs, and a small hair tuft emerging from the central punctum (Figure 2). Histologic examination confirmed the presence of an intradermal melanocytic nevus along with dilated folliculosebaceous units containing several cross-sectioned hair shafts (Figure 3). The second case involved a 30-year-old man who presented with a micropapular eruption on both flanks. Dermoscopy showed multiple vellous hairs erupting through the follicles (Figure 4).
Pozo L, Bowling J, Perrett CM, Bull R, Diaz-Cano SJ. Dermoscopy of Trichostasis Spinulosa. Arch Dermatol. 2008;144(8):1088. doi:10.1001/archderm.144.8.1088