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Diagnostic value of exclamation mark hairs
1Department of Dermatology, Chonbuk National University Medical School, Chonju, Republic of Korea.
Dermatology (Basel, Switzerland)
|January 1, 1993
Summary
Exclamation mark hairs are not exclusive to alopecia areata (AA). While frayed hairs suggest AA, blunt hairs are more common in trichotillomania, preventing misdiagnosis.
Area of Science:
- Dermatology
- Pathology
Background:
- Exclamation mark (EM) hairs are often considered pathognomonic for alopecia areata (AA), potentially leading to misdiagnosis.
- The presence of EM hairs has also been noted in other conditions, such as trichotillomania.
Observation:
- A comparative study analyzed EM hairs from 9 cases of AA and 2 cases of trichotillomania using light microscopy.
- Two distinct types of EM hairs were identified: those with frayed distal ends and those with blunt distal ends.
Findings:
- The majority of EM hairs in AA cases (77.8%) exhibited frayed distal ends.
- Conversely, the majority of EM hairs in trichotillomania cases (82.2%) presented with blunt distal ends.
Implications:
- The findings suggest that EM hairs, even those with frayed ends, are not definitively pathognomonic for AA.
- Distinguishing between frayed and blunt EM hairs may aid in differentiating AA from trichotillomania and improving diagnostic accuracy.