Epidermal growth factor receptor inhibitors, oral retinoids, sodium valproate, and carbamide perhydrate have been known to induce pili torti.

[65] Drugs related to pili torti include epidermal growth factor receptor inhibitors,[69][70] oral retinoids,[71] sodium valproate,[72] and carbamide perhydrate.

[73] Uneven growth of the outer root sheath cells is the source of hair twisting in hereditary forms.

[74] In acquired forms, the hair follicle is deformed and rotational forces are generated by a perifollicular inflammation followed by fibrosis.

Low magnification trichoscopy in pili torti reveals the hair shafts bent at random intervals and at varied angles.

[4] Upon microscopic inspection, the shaft exhibits irregularly spaced clusters of three or four twists at random intervals.

[8] Acquired pili torti may result from medication side effects or be linked to a variety of systemic and dermatological disorders.

Additional techniques of care include dyeing, braiding, heat treatments, avoiding over-grooming, and sleeping on a satin pillowcase.

[22] Topical minoxidil has been proposed as a good therapeutic alternative for individuals with higher fragility in their hair shaft abnormalities.

[4] In 1932, Ronchese and Galewsky separately published the first descriptions of pili torti, also referred to as "twisted hair.