Abstract: A 53-year-old female patient was diagnosed with atopic dermatitis in another hospital one year prior and received dupilumab therapy for a total of nine administrations. Subsequently, scaly erythema, papules accompanied by pruritus emerged on her trunk and extremities. Pathological examination of the skin lesions in our hospital confirmed psoriasis. Further inquiry about her medical history revealed a personal and familial history of psoriasis. After a confirmed diagnosis of psoriasis, she was treated with cyclosporine for four months, and the skin lesions gradually subsided. During the tapering and discontinuation of cyclosporine, the patient developed thickening, opacity and pain in the nails of both hands. Auxiliary examinations showed positive for interferon-gamma release assay (IGRA) and purified protein derivative (PPD) skin test. The final diagnoses were nail psoriasis and latent tuberculosis infection (LTBI).One month after initiating preventive anti-tuberculosis treatment, the patient was prescribed upadacitinib extended-release tablets. Two months later, significant improvement was observed in the nail lesions; after four months of treatment, the nails returned to normal. During the follow-up period, no new psoriatic lesions or adverse drug reactions occurred. In addition, this paper summarizes relevant literature and discusses the potential mechanisms of dupilumab-induced psoriasis, therapeutic options for nail psoriasis, as well as the advantages and precautions of upadacitinib in the management of refractory nail psoriasis.

Key words: atopic dermatitis, psoriasis, dupilumab, JAK inhibitor, upadacitinib