Ivarmacitinib in atopic dermatitis presenting with prurigo nodularis-like lesions and alopecia areata: a case report.

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disorder characterized by intense pruritus, eczematous lesions, and significant impairment of quality of life. In severe or chronic cases, AD can present with diverse atypical phenotypes, among which prurigo nodularis (PN)-like lesions are clinically challenging due to their recalcitrance to conventional therapies. Patients with severe AD are also at an increased risk of comorbid immune-mediated diseases, such as alopecia areata (AA), a non-scarring hair loss disorder driven by aberrant immune responses. Ivarmacitinib, a highly selective oral Janus kinase 1 (JAK1) inhibitor, has been approved by the National Medical Products Administration (NMPA) of China for moderate-to-severe atopic dermatitis (April 2025) and alopecia areata (June 2025). Herein, we report a case of a 28-year-old male patient with a long-standing history of AD who developed generalized PN-like lesions and concurrent AA (with a 2-year disease duration) and androgenetic alopecia (AGA). Conventional therapies including topical corticosteroids and antihistamines failed to yield satisfactory outcomes. Following treatment with ivarmacitinib (8 mg once daily), the patient showed rapid improvements in skin lesions, pruritus, and hair regrowth. This case suggests that ivarmacitinib may be beneficial for complex AD phenotypes with comorbid immune-mediated hair loss.