Real‐data on the use of baricitinib in adolescents with severe alopecia areata

Dear Editor, Alopecia areata (AA) is a common autoimmune disease that frequently affects children, presenting as patchy hair loss but often progresses to alopecia totalis (AT) and alopecia universalis (AU).1 Recent research has demonstrated the beneficial effect of Janus kinase (JAK) inhibitor, tofacitinib, in the treatment of childhood AA.2 We presented a case series of baricitinib treatment in five adolescents aged 7– 18 with AT or AU who had previously failed to conventional therapy. Unlike tofacitinib inhibiting JAK1/3, baricitinib is a novel JAK inhibitor targeting JAK1/2. Before initiating treatment with baricitinib, all patients completed laboratory tests (complete blood count, metabolic panel, and fasting lipid panel) and an infection screen (HIV, hepatitis B, C, and tuberculosis), followed by laboratory testing every 2 months at our hospital or their local hospital. Currently, baricitinib is not commonly administered to children. In the treatment of juvenile dermatomyositis, baricitinib is taken between 4 and 8 mg per day, based on the patient's weight.3 In adult AA patients, 4 mg of baricitinib daily had higher clinical effectiveness than 2 mg.4 Here, three patients weighing <50 kg received a daily dose of 2 mg baricitinib and two patients weighing more than 50 kg were given 4 mg baricitinib daily. We use the severity of alopecia tool (SALT) to assess efficacy. Except for patient 3 who showed no improvement, the other four patients demonstrated a significant decrease in SALT (Table 1). However, patients 1 and 2 exhibited varied degrees of hair loss after baricitinib discontinuation. Patient 1 presented with just occasional moderate hair loss. Patient 2's SALT level decreased to 18 after 5 months of baricitinib treatment, however, she relapsed into hair loss after discontinuing baricitinib while maintaining minoxidil spray and vitamin complex tablets, leading her SALT level to rise to 62, which is still lower than her baseline SALT level (Figure 1). Four months after she retook 2 mg of baricitinib per day, her SALT level dropped to 28. After 4 months of baricitinib treatment, patient 5, who was the youngest patient at 7 years old, saw a SALT decrease of 80 and an improvement in her nail symptoms. Patient 5 was the only one to report adverse effects. During baricitinib administration, patient 5 with congenital preauricular fistula experienced three instances of mild infection, which is more frequent than previously. Since no more abnormalities were identified, her caregiver opted to continue administering baricitinib. The effectiveness of baricitinib in treating adult AA has been demonstrated by phase III clinical trials.4 In this cohort, baricitinib had quicker and more favourable results than traditional treatments for severe adolescent AA. Nonetheless, nonresponder, adverse events and recurrences still exist. Due to the small size of this cohort and the lack of a longterm, multicentre trial, the safety and efficacy of baricitinib have yet to be examined.