Intestinal pseudo-obstruction with life-threatening manifestations in a patient with adult-onset Still’s disease reactivation

Introduction: Adult-onset Still’s disease (AOSD) is a rare systemic autoinflammatory disorder with heterogeneous clinical manifestations and potentially life-threatening complications. Gastrointestinal manifestations are rarely reported, with only a few cases of intestinal pseudo-obstruction described in the literature. Case description: We report the case of a 35-year-old man with a history of AOSD in remission who developed acute non-bloody diarrhoea, progressive abdominal distension, and high-spiking fever. Imaging demonstrated small-bowel distension in the absence of mechanical obstruction. A thorough diagnostic workup ruled out infectious, metabolic, neoplastic, and autoimmune aetiologies, including Crohn’s disease and vasculitis. Endoscopic biopsies revealed interstitial colitis, and faecal calprotectin was elevated, consistent with intestinal inflammation. Laboratory findings showed marked systemic inflammation with hyperferritinaemia, reduced glycosylated ferritin fraction, and substantially elevated interleukin-18, supporting an AOSD disease flare. The final diagnosis was AOSD-associated intestinal pseudo-obstruction. Treatment with corticosteroids and anakinra led to rapid clinical improvement and rapid control of systemic inflammation. Conclusion: This observation highlights that acute intestinal pseudo-obstruction may represent an uncommon but clinically significant manifestation of AOSD flare. Cytokine-driven gut dysmotility, particularly through IL-1 and IL-18 signalling, appears to be a plausible pathophysiological mechanism. Timely recognition and early introduction of targeted immunomodulatory therapy are critical to prevent severe complications.