Alopecia areata (AA) is the most common immune-mediated hair loss disorder with a life-time prevalence of 2%. The pathogenesis of AA is not completely understood, but interferon gamma (INF-γ) and Janus kinases (JAK) may play a key role. Here, we present a case involving a male patient with psoriasis and psoriatic arthritis, who exhibited a rapid hair loss, diagnosed as AA, during ciclosporin treatment. As ciclosporin was unable to control his psoriasis, the treatment was changed to methotrexate injections, but the hair loss progressed into alopecia universalis. During treatment with the oral JAK inhibitor tofacitinib, the patient presented an almost complete hair remission on the scalp and partly on the eyebrows, eyelashes, beard, and chest. Furthermore, the patient experienced no joint complaints and his psoriasis was improved. Based on these findings, JAK inhibitors may be an optional treatment in complicated cases involving both rheumatological and dermatological diseases.