A 29-year-old Mexican American man described a several-year history of a spiny eruption on the back of his neck. The area had been treated unsuccessfully with corticosteroid creams.
Physical examination showed several well-demarcated clusters of abundant discrete follicular papules. The papules, which measured approximately 1 mm in diameter, were slightly hypopigmented and monomorphous, and most had a central keratinous spine (Figure 1 and Figure 2). The skin over the triceps, the anterior aspect of the thighs, and the buttocks was uninvolved. A punch biopsy specimen was obtained (Figure 3).
Strickling WA, Norton SA. Spiny Eruption on the Neck. Arch Dermatol. 2000;136(9):1165-1170. doi: