Predictive Value of Grooming Behavior for Development of Dermatitis in Selectively Bred P Rats as a Model of Trichotillomania Hair Pulling Disorder.

Debra Hickman,Richard Bell,Anjali Prakash

doi:10.3390/vetsci9020089

Debra Hickman, Richard Bell + Show 1 more

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https://doi.org/10.3390/vetsci9020089

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Abstract

Trichotillomania (TTM) is a body-focused repetitive disorder affecting as much as 0.5 to 2% of the population, with women four times more likely to be affected than men. This disorder causes impairment in daily function and significant distress. A potential animal model for this disorder is the inbred C57BL/6J mouse which displays clinical signs and behavioral characteristics similar to those described for people affected by this disorder. Because alcohol-preferring P rats also display similar clinical signs and behavioral characteristics, it was hypothesized that this selectively bred stock could be an additional animal model. In this study, 112 female P rats were recorded on digital media for 15 min after being sprayed with a mist of water and assessed for grooming patterns—oral, manual, and scratching. Significant elevations in scratching and oral grooming behavior were predictive of the future development of skin lesions. These findings suggest that P rats may be an additional model to study TTM, with the advantage of increased genetic variation (i.e., non-inbred) which mirrors the human population. The use of this model may help to identify preventative and therapeutic interventions for humans and other animals with similar body-focused repetitive disorders.

Highlights

Received: 9 October 2021Trichotillomania (TTM, “hair-pulling disorder”) is defined by the American PsychiatricAssociation as an obsessive compulsive disorder (OCD) [1]
P rats were transferred to the Indiana University School of Medicine, and they have been maintained by the Indiana
There were no significant differences in the relative frequency of manual grooming (p = 0.7147) or scratching (p = 0.1324) in rats that developed lesions as compared to the rats that did not develop lesions using the Kruskal–Wallis test

Summary

Introduction

Received: 9 October 2021Trichotillomania (TTM, “hair-pulling disorder”) is defined by the American PsychiatricAssociation as an obsessive compulsive disorder (OCD) [1]. People who are affected by TTM pull their hair out, creating bald patches, resulting in exposed skin and tissue, with the disorder being typically diagnosed in childhood or adolescence. The affected areas can include anywhere there is hair, with the scalp, eyebrows, eyelashes, pubic area, and beard representing the most common locations [1]. 92.5% of the adult patients presenting to a TTM clinic, though it has been hypothesized that men may be better able to hide the behavior through interventions such as shaving the head. The diagnostic criteria for TTM include the recurrent pulling out of one’s hair that results in noticeable hair loss, repeated attempts to decrease or stop the hair-pulling behavior, and clinically significant distress or impairment in social, occupational, or other areas of functioning [1]. The condition must not be accounted for by another mental disorder or be due to a general medical condition (e.g., dermatologic condition)

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