Table I.
Trichoscopic features of trichotillomania
| Trichoscopic feature | Prevalence Ranges, % | Prevalence Mean, % | Sensitivity % | Specificity % | Positive predictive value % | Negative predictive value % |
|---|---|---|---|---|---|---|
| Hook hairs | 11.1−56.8 | 43.1 | 43.5 | 100.0 | 100.0 | 93.6 |
| Coiled hairs | 4.3−100.0 | 36.8 | 29.0 | 99.6 | 90.0 | 92.4 |
| V-sign | 20.0–70.0 | 50.4 | 48.9 | 99.0 | 86.3 | 93.5 |
| Hair powder | 10.0−88.9 | 35.6 | 30.6 | 97.9 | 68.4 | 90.3 |
| Trichoptilosis | 34.1−100.0 | 57.5 | 50.5 | 97.5 | 67.1 | 95.2 |
| Flame hairs | 25.0−100.0 | 37.1 | 36.2 | 96.5 | 52.1 | 93.5 |
| Tulip hairs | 10.0−47.7 | 36.4 | 47.7 | 89.6 | 38.2 | 92.7 |
| Broken hairs | 80.0−100.0 | 99.5 | 99.3 | 62.9 | 18.7 | 99.9 |
| Black dots | 27.3−100.0 | 66.7 | 65.1 | 61.7 | 12.7 | 95.4 |
The prevalence ranges and mean are based on studies in which given feature was evaluated (5, 8–17, 20, 22). The sensitivity, specificity, PPV and NPV were calculated based on original articles (5, 8–10, 14, 16, 17, 20).