Clinicopathological Observation in Trichotillomania and Pathologs after Hair Plucking in Rabbits

Chung, Tae Ahn; Kown, Kyung Sool; Jang, Ho Sun; Oh, Chang Keun; Cho, Si Hyung

Abstract

BACKGROUND: Trichotillomania appears as incomplete alopecia due to patients own repeated manipulations of the hair. But there are few available clinicopathologic data in Korea.
OBJECTIVE
The purpose of this study was to evaluate the clinicopathological feature of trichotillomania and the experimental pathologic findings after hair plucking in rabbits. METHOD: Through retrospective study on patients who were diagnosed as trichotillomania from 1988 to 1997 at the Department of Dermatology in Pusan National University Hospital, we observed the clinical and histopathological findings in 20 cases of trichotillomania as well as histopathologic changes of hair follicle and associated structure after hair plucking in rabbits with 4 days interval.
RESULTS
1. The mean age of onset was 15.7 years and female were 12 cases(60%). 2. The school age(between 7 and 18 years) was most common as 15cases(75%) 3. Among initial sites of involvement, parietal region was the most common(10 cases, 55%), followed by frontal(5 cases, 25%), temporal(2 cases, 10%), and occipital(2 cases, 10%) region. 4. Some patients complained pruritus(25%), chronic headache(10%) and had onychophagia (20%), trichophagia(5%) and thumb sucking(5%). 5. Many patients were not typical in history, and 14 cases(70%) denied hair-plucking history. 6. Results of twelve patients with psychiatric consultation revealed obsessive disorder(4 cases, 33%), social phobia(2 cases, 17%) and dysmorphic disorder(1 case, S%). 7. The most common presumptive triggering factor was mental stress related to school work(5 cases, 25%). 8. The characteristic findings of histopathologic examination in 20 cases were empty hair follicles without perifollicular infiltration(100%) and increased catagen hair(90%) with normal anagen hair(85%), trichomalacia(40%). 9. In experimental hair plucking of rabbit, soon after hair plucking, dilated empty root sheaths, perifollicular hemorrhage were observed. These findings are similar in trichotillomania. Catagen evolution, sebaceous proliferation and hyperplasia at 4th day, prominent bulge region at 8th day, growing epithelial sheaths into deep dermis at 12th day, many anagen hair at 20th day were observed.
CONCLUSION
Trichotillomania was more frequent in young than adolescent and female than male. Histopathologically, the most characteristic finding was increased catagen hair without perifollicular inflammation. In hair follicle regeneration of rabbit after plucking, all hair follicles changed into catagen and telogen stage simultaneously and new hair growth was observed.