Hair loss on legs went largely undiagnosed, but is now thought to be quite common. While the overall causes are still being explored, the primary culprit is currently thought to be friction from socks and footwear. There is some debate as to what proportion is caused by friction, and what by androgen deficiency, minor vascular disease, rash of various causes, or thyroid deficiency.
Frictional alopecia
Triangular alopecia
Traction alopecia
Hot comb alopecia
Pressure alopecia
Hypertrichosis cubiti
Central centrifugal cicatricial alopecia
Onychogryphosis