Alopecia areata: treatment options

Alopecia areata is an autoimmune condition in which the immune system attacks hair follicles, usually causing round bald patches. The follicles are not destroyed, so hair can grow back. Treatment is chosen by severity: limited patches are treated locally, while extensive hair loss may call for systemic treatment, where JAK inhibitors are now the approved options.

How is severity measured?

Dermatologists use the Severity of Alopecia Tool (SALT), which estimates the percentage of the scalp without hair. A 2024 European expert consensus considers a SALT score of 20 or more, meaning a fifth of the scalp or more, a commonly accepted indication for systemic treatment.

Which treatments are used?

For limited patches

Local treatment is the usual first step: corticosteroids applied to the skin or injected into the patches, and topical immunotherapy in some cases. A 2025 review notes that these older treatments work inconsistently and raise questions about long-term use, which is why newer options matter.

For extensive or severe hair loss

JAK inhibitors block a signalling pathway that drives the immune attack on the follicle. Three have been approved by the US FDA for alopecia areata: baricitinib, ritlecitinib and deuruxolitinib. In their pivotal trials, about 35 to 40% of patients on baricitinib reached a SALT score of 20 or less at 36 weeks, 23% on ritlecitinib at 24 weeks and 31% on deuruxolitinib at 24 weeks. In Europe, baricitinib (adults) and ritlecitinib (age 12 and over) are approved for severe disease. Other systemic medicines, such as corticosteroids, ciclosporin, methotrexate and azathioprine, are used off-label.

What about exosomes?

Exosomes are being studied for cases that do not respond to standard treatment. Professor Nilforoushzadeh's group reported two patients with refractory alopecia areata who improved after a single session of adipose-derived exosomes, with SALT scores falling from 79.6 to 59.6 and from 70.2 to 58.6 at three months. A 2025 systematic review found encouraging laboratory and animal results, but only two clinical studies, and called for randomised trials. For now, exosomes are an option to discuss in refractory cases, not a replacement for approved treatment. The evidence is set out in exosomes for hair loss.

Can alopecia areata come back?

Yes. The course is unpredictable: hair may regrow on its own, and new patches can appear later. Relapse after stopping treatment is common, which is part of planning treatment with a dermatologist. Hair transplantation is generally not used for alopecia areata, because the immune process can affect transplanted follicles too; the hair restoration guide explains how the conditions differ.