# Adult-Onset Still’s Disease: An Atypical Presentation Refractory to Standard Treatment

## TL;DR

A young woman with Southeast Asian heritage developed a rare autoimmune condition triggered by a virus, showing unusual symptoms and treatment challenges.

## Contribution

This case highlights an atypical presentation of AOSD complicated by macrophage activation syndrome and treatment resistance.

## Key findings

- AOSD was diagnosed in a young woman with parvovirus B19 infection and hemophagocytic lymphohistiocytosis.
- The case demonstrates diagnostic and treatment challenges in AOSD complicated by macrophage activation syndrome.
- Unintentional weight loss, polyarthritis, and urticarial rash were prominent features in this atypical AOSD case.

## Abstract

A previously healthy young female of Southeast Asian descent presented with a two-week history of polyarthritis, urticarial rash, sore throat, and 8.6 kg of unintentional weight loss. The initial workup revealed a positive parvovirus B19 polymerase chain reaction with hyperferritinemia. The patient was diagnosed with adult-onset Still’s disease (AOSD) secondary to parvovirus B19 infection. Bone marrow biopsy also showed evidence of hemophagocytic lymphohistiocytosis. Viral and bacterial infections may trigger AOSD in genetically susceptible hosts either via an unknown mechanism or by direct cytotoxic effect. This case shows an atypical presentation of AOSD, as well as the challenge in diagnosing and treating AOSD complicated by macrophage activation syndrome refractory to standard treatment.