Barbering in mice: a model for trichotillomania

Barbering (excessive grooming causing hair loss) in mice resembles trichotillomania (uncontrollable hair pulling) in humans in several respects and may be a useful model of trichotillomania, especially for investigating the complex genetic and environmental interactions

Our interest in systemic lupus erythematosus led us to develop an animal model of lupus by immunising rabbits or mice with peptides that are targets of autoimmune sera from people with lupus.Animals immunised with these peptides developed autoimmunity to the entire Ro ribonucleoprotein as well as to other autoantigens.1^–3 During this study, we observed the loss of facial hair in a groupof five experimental mice, possibly a sign of alopecia, a symptom of lupus. When we observed the characteristics of the hair loss and the fact that one of the mice had not lost her facial hairwhereas the other four had, we realised that this was a clear case of “barbering.”

Barbering in mice

Fur and whisker trimming by laboratory mice is referred to as “barbering.” Laboratory mice housed in groups are frequently found with their facial hair and whiskers removed (figure). In one study facial alopecia was found in three of four adult female Fisher 344 rats that shared a cage for two months.4 The hairless areas were non-pruritic and without any association with pathogenic skin bacteria, dermatophytes, or ectoparasites. The authors found that when the unaffected rat was placed with a different set of rats, facial alopecia became evident in those animals within six days, and the hair of the original cagemates grew back within 21 days. Thus the alopecia was found to be caused by a dominant female “barber.”4

Barbering in mice: the “barber” is …