Lichen spinulosus is a rare skin disorder characterized by follicular keratotic papules that are grouped into large patches.^[2] It is a variant of keratosis pilaris named for its resemblance to a patch of lichen.

It appears as a cluster of keratotic spines that resemble sandpaper and 2–5 cm hypopigmented or skin-colored follicular papules.^{[citation needed]} The lesions typically appear on different parts of the skin and last for a few weeks or months.^[3]

It could be inherited or linked to substances like gold, arsphenamine, thallium, vitamin A deficiency, diphtheria toxin, atopy, lithium medication, Hodgkin's disease, Crohn's disease, HIV, or alcoholism.^[3]

The histologic observations reveal a dermal lymphohistiocytic infiltration focused around hair follicles.^[3]

Treatments include topical keratolytics and emollients such as urea, adapalene, salicylic acid, vitamin A, tretinoin, and tacalcitol.^[3]

• Hook nail
• List of cutaneous conditions

• SJ, Friedman (1990). "Lichen spinulosus. Clinicopathologic review of thirty-five cases". Journal of the American Academy of Dermatology. 22 (2 Pt 1). J Am Acad Dermatol: 261–264. ISSN 0190-9622. PMID 2179296. Retrieved 2024-03-19.
• Kabashima, R; Sugita, K; Kabashima, K; Nakamura, M; Tokura, Y (2009). "Lichen Spinulosus in an Alcoholic Patient". Acta Dermato Venereologica. 89 (3). Medical Journals Sweden AB: 311–312. doi:10.2340/00015555-0600. ISSN 0001-5555. PMID 19479136.

• DermNet
• Cleveland clinic