EVIDENCE-BASED ANSWER
IT’S UNCLEAR; there are no validated effective treatments for alopecia areata (AA). Topical immunotherapy (squaric acid dibutylester [SADBE] and diphenylcyclopropenone [DPCP]) induces the most signifi cant short-term hair regrowth in children with severe AA (strength of recommendation [SOR]: C, 4 small individual cohort studies and 1 moderately sized retrospective case review). Intralesional steroids can induce hair regrowth greater than 50% in children with limited AA (SOR: C, 1 retrospective cohort study).
Other commonly used treatments—topical and oral corticosteroids, topical cyclosporine, photodynamic therapy, and topical minoxidil—have no benefit over placebo (SOR: A, 14 randomized controlled trials [RCTs] and 3 within-patient studies).
Evidence summary
AA is a common inflammatory condition that causes hair loss and subsequent social consequences. Spontaneous remission occurs in 34% to 50% of patients within 1 year.1 Many trials of commonly used AA treatments have identified no significant patient benefits. A 2008 Cochrane review that examined 17 studies (14 RCTs and 3 within-patient studies) of AA interventions in 540 participants found no clinically significant hair regrowth (>50%) when patients were treated with topical corticosteroids, cyclosporine, minoxidil, photodynamic therapy, or oral corticosteroids.2
Documenting patient outcomes is problematic because of spontaneous resolution and frequent relapses.2 Moreover, few quality-controlled trials have studied children, and no long-term, randomized outcome trials of AA treatments exist.
Intralesional steroids and SADBE show results
In a moderately sized retrospective cohort study in Singapore (392 patients <16 years), 57% of patients experienced more than 50% improvement after 12 weeks of intralesional steroids for limited AA, and 75% showed similar improvement after 24 weeks. Of 43 children treated with anthralin, only 10 with limited AA showed more than 50% clinical improvement within 6 months.3 Fifty-four patients with extensive AA received SADBE; 74% experienced greater than 50% hair regrowth at 6 months.3
SADBE effects aren’t long-lived
A 1996 individual cohort study of 33 children (6*#8211;14 years of age) with extensive AA who were treated with SADBE once a week for a year showed a complete regrowth rate of 30.3%. Only 9% of the children maintained total or partial regrowth during long-term follow-up (mean 6 years), however.4
In another individual cohort study, 28 pediatric patients with extensive AA had mixed results with 2% SADBE used once a week for a year.5 Nine patients (32.1%) showed total or acceptable hair growth; 6 (21.4%) had diffuse regrowth but thinner than normal hair. Eighty-seven percent of patients relapsed within 6 months of discontinuing therapy.5
Studies of DPCP are too small
A 1996 small individual cohort investigation recorded a 40% response rate (90%–100% regrowth) to DPCP in 10 pediatric patients with extensive AA who were treated for an average of 8.6 months. The same study found cosmetically acceptable growth in 27% of patients (4 of 15 patients 4–15 years of age) treated for an average of 9.6 months.6