What causes some head hair to grow with the texture and appearance of pubic hair?

Head hair that takes on a pubic‑hair look (thick, dark, coarse, and tightly coiled) can happen for a few different reasons. The available evidence points to three main causes.

Acquired progressive kinking from androgenetic alopecia

This is a form of pattern baldness where hair on the androgen‑sensitive parts of the scalp gradually grows in kinked, darker, and more like pubic hair. It is an acquired change (develops over time) and is often linked to a poorer outlook for keeping that hair.[1][2]

Yeast overgrowth in the scalp

An overgrowth of yeast inside the scalp pores can sometimes disrupt normal hair growth, causing the strands to come out with a “wonky” or abnormal texture—including the thick, kinky quality that resembles pubic hair.[3]

Woolly hair syndrome (genetic)

Woolly hair syndrome is a rare congenital (present from birth) group of disorders that makes the scalp hair extremely kinky and tightly coiled. The problem lies in the hair shaft’s structure itself, usually because of mutations in genes like JUP, DSP, DSC2, or KANK2. These mutations weaken the desmosomes (the “glue” that holds hair cells together), which makes the hair more fragile and gives it that coiled, pubic‑like appearance.[4][5][6][7][8][9]