traction alopecia and trichotillomania.In traction alopecia, hair loss is due to excessive and chronic pulling of the hair which is more prevalent in people who braid or knot their hair.

• 牵引创伤性脱发一般归咎于头发受到过度和慢性的拉拔，在喜欢给自己头发编辫子或打结的人群中较常见。