Overview
Definition
Autoimmune disease causing non-scarring hair loss.
Epidemiology
Lifetime risk of ~2%. Can occur at any age.
Etiology & Risk Factors
- Autoimmune attack on hair follicles (T-cell mediated)
- Genetic susceptibility
Clinical Symptoms
- Sudden onset of well-defined, round or oval patches of hair loss
- Exclamation mark hairs at the periphery
- Nail pitting
- No scalp inflammation or scarring
Clinical Approach
Diagnosis
- Clinical diagnosis
- Hair pull test (positive at margins)
Management
- Intralesional corticosteroids (Triamcinolone)
- Topical immunotherapy
- JAK inhibitors (Baricitinib) for severe cases
- Spontaneous resolution common in mild cases
Complications
- Alopecia totalis (total scalp hair loss)
- Alopecia universalis (total body hair loss)
- Psychological distress