ABSTRACT
Different investigators have described this condition using a variety of names, including whisker-eating, hair-nibbling and whisker-trimming, alopecia due to hair-chewing, behavior-associated alopecia areata in mice , and over-grooming. Hair shafts are present within follicles in alopecic areas; however, the shafts may be deformed. Foreign body granulomas may develop in the hypodermal fat associated with the presence of broken hair shafts. There are two major types of vibrissae: primary (mystacial vibrissae) and secondary (supraorbital, post-orbital, post-oral, intra-ramal, and ulnar-carpal vibrissae). Alopecia areata has recently been reported to occur in older C3H/HeJ mice. Neurogenic alopecia has been described in dogs, and domestic and captive wild felids. This disease resembles human trichotillomania because it is self-induced rather than a dominant group behavior, as seen with barbering in mice. Neurological abnormalities have not been thoroughly investigated in animals with these behavioral patterns, so it is possible that some forms may be very homologous to human trichotillomania.
