Atypical cutaneous presentation of AOSD with persistent itchy urticaria: A case report

Adult-onset Still's disease (AOSD) is a rare multisystem disorder considered a complex autoinflammatory syndrome. The clinical and biological features of AOSD typically include a high fever with arthritic symptoms, evanescent skin rash, sore throat, striking neutrophilic leukocytosis, hyperferritinemia, and abnormal liver function. The typical rash and fever are important diagnostic clues for AOSD. Here, we report a case of atypical rash manifesting as persistent itchy urticaria.

A 57-year-old female presented with a 6-day history of fever. During her hospital stay, she progressively developed rashes that were not associated with fever, primarily distributed on her back and the distal extremities, and associated with pronounced itching. The rash was initially suspected to be urticaria; however, the patient exhibited a poor response to antihistamines. After malignancies and other rheumatic diseases were excluded, the diagnosis leaned towards AOSD based on diagnostic criteria. The patient's fever was well controlled with the initiation of glucocorticoids, and no further rashes were observed.

Although the patient exhibited atypical rashes, after ruling out malignancies and other rheumatic diseases, she met 2 major and 3 minor criteria. Based on Yamaguchi's criteria, the patient was diagnosed with AOSD.

Initially, the patient was administered an intravenous infusion of methylprednisolone at 40 mg once daily. This was later transitioned to oral administration with gradual dose reduction.

Follow-up at 1 year showed no recurrence of the rash, with a stable condition and no relapse.

This case provides valuable insights for the early diagnosis of AOSD, emphasizing the importance of considering this diagnosis even when presenting with atypical skin rash.