Alopecia Areata

Alopecia areata (AA) is a common, T-cell mediated autoimmune disease of the hair follicle causing non-scarring, patchy hair loss, with a lifetime risk of about 2%.

• Onset at any age, often under 30 years. Family history in 10 to 20%.
• Associations: atopy, thyroid disease (Hashimoto), vitiligo, Down syndrome, and autoimmune polyendocrine syndrome type 1.
• Course is unpredictable: about 50% of patchy cases recover within a year; extensive disease (alopecia totalis, universalis) has poor remission rates.

• Well defined round or oval patches of smooth skin with no scarring. Exclamation mark hairs at the margin.
• Patterns: patchy, reticular, ophiasis (band like at the occipital margin), sisaipho, totalis (entire scalp), and universalis (all body hair).
• Nail pitting, trachyonychia, and red lunulae in 10 to 40%.
• White hairs spared (rapid "overnight" greying), and psychological distress.

• Clinical, with dermoscopy: yellow dots, black dots, broken hairs, and exclamation mark hairs.
• Severity: SALT score (Severity of Alopecia Tool); severe disease is at least 50% scalp loss.
• Biopsy if unclear: peribulbar lymphocytic "swarm of bees" infiltrate, miniaturised follicles.
• Check TSH, thyroid antibodies, ferritin, vitamin D, and ANA if clinical suspicion.
• Exclude trichotillomania, tinea capitis, telogen effluvium, secondary syphilis, lupus, and lichen planopilaris.

• Limited patchy disease: intralesional triamcinolone acetonide 2.5 to 10 mg/mL (use 2.5 mg/mL on face and 5 to 10 mg/mL on scalp), 0.1 mL per cm2 every 4 to 6 weeks (maximum 20 mg per session); topical clobetasol 0.05% or minoxidil 5% twice daily.
• Extensive disease (JAK inhibitors, first line when available):
  • Baricitinib 2 mg daily, increasing to 4 mg daily (adults).
  • Ritlecitinib 50 mg daily (age 12 and above).
  • Deuruxolitinib 8 mg twice daily.
  • Tofacitinib 5 to 10 mg twice daily (off label).
  • Monitor FBC, lipids, LFTs, creatinine, and consider screening for TB, hepatitis B, and VTE risk; relapse is common after stopping.
• Other systemic options: methotrexate 15 to 25 mg weekly (often with prednisolone), sulfasalazine 2 to 3 g daily, ciclosporin 3 to 5 mg/kg, and oral prednisolone pulses (e.g., 200 mg once weekly) for rapid progression.
• Topical immunotherapy: diphenylcyclopropenone (DPCP) weekly, with response in 30 to 60%.
• Camouflage (wigs, microblading, scalp micropigmentation), sunscreen, eye protection if eyelashes lost, and psychological support.