Fox mange, a disease in which the hair falls out: Alopecia can be explained as the absence of the hair from skin areas where it normally is present, especially of the head.

Alopecia is one characteristic of mange. It affects both men and women of all ages.

Mange is defined as a contagious scabies-like dermatitis occurring in various animals, including cattle, sheep, horses, dogs, cats, foxes, rabbits, rats, and gallinaceous birds (domestic fowls); caused by any of several of the mange mites.

Hair loss caused by injury to the scalp: Common causes of traumatic alopecia include the use of caustic hair straighteners, especially those that include lye as an ingredient, stress traction injury from tight rollers and braiding, over heating of the hair shafts; and the compulsive pulling out of hair (trichotillomania).