What is the management of alopecia areata?

Alopecia Areata: Causes, Diagnosis, Investigations, and Management

Causes

Alopecia areata is an autoimmune condition where CD8+ T-cells mount an immune attack against hair follicles, leading to non-scarring hair loss. 1, 2

• The exact trigger for this autoimmune response remains unclear, but the disease affects approximately 2% of the population worldwide 2
• The condition has an unpredictable course that is not easily altered by treatment 3

Diagnosis

Diagnosis is primarily clinical, based on characteristic patterns of hair loss on examination. 4

• Look for well-demarcated patches of complete hair loss, typically circular or oval in shape 4
• Examine for "exclamation point" hairs at the margins of active patches 4
• Assess the extent of involvement: limited patchy (few patches), extensive patchy (multiple patches), alopecia totalis (complete scalp hair loss), or alopecia universalis (complete body hair loss) 1
• Check for nail changes (pitting, trachyonychia) which may be present in some patients 4

Investigations

No specific laboratory investigations are required for diagnosis, as alopecia areata is a clinical diagnosis. 4

• Disease severity should be assessed using the SALT score (Severity of Alopecia Tool) or Alopecia Areata Scale (AAS) 1
• A SALT score ≥20 or moderate-to-severe disease on AAS constitutes an indication for systemic therapy 1
• Consider screening for associated autoimmune conditions if clinically indicated 4

Management

Initial Decision: To Treat or Not to Treat

For patients with limited patchy hair loss of short duration (<1 year), observation without treatment is a legitimate and often preferred option, as spontaneous remission occurs in up to 80% of these cases. 4, 5

• Counsel patients that regrowth cannot be expected within 3 months of any individual patch developing 5
• Reassurance alone may be sufficient for mild cases 4
• For longstanding extensive alopecia, a wig may be superior to pursuing treatments with low likelihood of success 4, 5, 6
• Psychological support should be considered, especially for children showing behavioral changes 5

Treatment Algorithm Based on Disease Extent

Limited Patchy Hair Loss (First-Line)

Intralesional corticosteroids are the first-line treatment for limited patchy alopecia areata, particularly for fewer than five patches <3 cm in diameter. 4, 5, 6

• Use triamcinolone acetonide 5-10 mg/mL or hydrocortisone acetate 25 mg/mL 4, 5
• Inject 0.05-0.1 mL just beneath the dermis in the upper subcutis, producing a tuft of hair growth approximately 0.5 cm in diameter 4, 6
• Administer monthly injections; 62% of patients achieve full regrowth with this regimen 4, 5, 6
• Response is better in those with fewer patches of smaller diameter 4
• This method is particularly suitable for cosmetically sensitive sites like eyebrows 4
• Common pitfall: Skin atrophy at injection sites is a consistent side-effect, particularly with triamcinolone 4
• Patient discomfort is the main limitation to multiple injections 4

Alternative: Potent topical corticosteroids (if intralesional injections are not tolerated) 5, 6

• Use clobetasol propionate 0.05% foam or ointment 4
• Evidence is limited: only 7 of 34 patients achieved ≥50% regrowth in one trial 4
• Under occlusive dressing (6 nights/week for 6 months), only 18% achieved long-term regrowth 4
• Folliculitis is a common side-effect 4

Extensive Patchy Hair Loss (First-Line)

Contact immunotherapy with diphenylcyclopropenone (DPCP) is the most effective treatment for extensive patchy alopecia areata, achieving worthwhile response in 50-60% of patients. 4, 5

• Sensitize with 2% DPCP solution applied to a small scalp area 4
• Two weeks later, begin weekly applications starting at 0.001% concentration 4
• Increase concentration at each treatment until mild dermatitis is achieved 4
• Initially treat one side of scalp to distinguish treatment response from spontaneous recovery 4
• Once regrowth occurs, treat both sides 4
• Critical caveat: DPCP is degraded by light; solutions must be stored in darkness and patients should wear a hat/wig for 24 hours post-application 4
• Response rates vary widely (9-87%), with lower success in extensive disease 4
• Important limitation: Availability is limited in many centers 6

Alopecia Totalis/Universalis

For alopecia totalis/universalis, contact immunotherapy may be attempted but success rates are low (approximately 17%), making a wig or hairpiece often the most practical solution. 5, 6

• The prognosis in longstanding extensive alopecia is poor 4
• Patients with extensive disease tend to be resistant to all forms of treatment 4, 5
• A wig is the most effective solution for quality of life in this population 5, 6

Systemic Therapies

Systemic corticosteroids and other immunosuppressants are not routinely recommended due to potentially serious side effects and inadequate evidence of long-term efficacy. 5

• Oral pulse corticosteroids (dexamethasone or prednisolone 5 mg/kg equivalent once every 4 weeks) combined with topical clobetasol under occlusion showed 56.9% achieving >75% regrowth in children, with best results in disease duration ≤12 months 7
• JAK inhibitors (baricitinib for adults, ritlecitinib for age ≥12 years) are EMA-approved for severe alopecia areata but represent newer options 1
• Off-label systemic options include cyclosporine, methotrexate, and azathioprine, though evidence is limited 1

Special Considerations for Children

Children may be treated similarly to adults, but intralesional corticosteroids are often poorly tolerated and many clinicians are reluctant to use aggressive treatments. 5

• Short-contact anthralin therapy has shown promise in children 3
• Combined oral pulse and topical corticosteroid therapy showed long-lasting results without serious side effects in pediatric patients 7
• Referral for psychological support is important for children showing withdrawal, low self-esteem, or failing at school 5

Critical Treatment Pitfalls

No treatment has been shown to alter the long-term course of alopecia areata; all therapies aim only to stimulate hair regrowth, not prevent future episodes. 4, 5, 3

• High spontaneous remission rates make efficacy assessment difficult, particularly in mild disease 4, 5
• Relapse rates are high even with initially successful treatment; patients must be forewarned 4
• Treatment can alter patients' attitudes toward their hair loss and make subsequent relapses more difficult to cope with 4
• PUVA therapy cannot be recommended due to high cumulative UVA exposure risk and inadequate evidence 4