Extensive subtypes of alopecia areata (AA) (totalis, universalis, or multifocal) still have no approved and effective treatments in Europe, although Janus kinase inhibitors, such as baricitinib, are promising treatments that have been recently approved by the FDA. Nowadays, the higher costs and the lower experience with Janus kinase inhibitors, provide more difficulties in its accessibility. On the other hand, different corticosteroids regimens have been evaluated with conflicting results from decades. In 2016, a new regimen of mini pulse corticosteroid therapy with oral dexamethasone (MPCT-OD) 0.1mg/kg/day twice per week for adult patients with alopecia areata totalis or universalis, was reported to be effective with a lower rate of adverse effects. We performed a retrospective and multicentric study to collect data from patients with extensive forms of alopecia areata who had received MPCTOD (0.1 mg/kg/day twice weekly of dexamethasone) for at least 24 weeks. We included adult patients (≥18 years) with extensive forms of AA (SALT index ≥ 10) that did not respond to previous treatments. Variables including epidemiological and clinical data were recorded. Therapeutic response was assessed through the % change in SALT score (from 0 to 100%) and the changes in eyebrow and eyelash alopecia index (EBA, ELA) from baseline to 24 weeks after the beginning of the treatment. Dexamethasone dosage, duration of the treatment, time until response, time to relapse, adverse effects, and discontinuation were also recorded.