Clinical features, imaging findings, and outcomes of acute abdominal pain in systemic lupus erythematosus: comparing mesenteric vasculitis, non-mesenteric vasculitis, and surgical conditions.

Objectives: To determine the spectrum, clinical features and outcomes in systemic lupus erythematosus (SLE) patients with acute abdominal pain (AAP).

Method: Medical records of SLE patients in a lupus cohort from January 1987 to June 2023 were reviewed. Patients with AAP requiring hospitalization were identified and categorized into 3 groups: lupus mesenteric vasculitis (LMV), non-LMV, and surgical AAP. Each AAP episode represented one patient.

Results: Of 1,538 patients in the cohort, 62 (4.03%) had 93 episodes of AAP. After exclusion, 31 patients had 39 LMV episodes, and 30 had 40 non-LMV episodes (19 due to surgical AAP). Seventy-six of the 79 AAP episodes (96.20%) were in females, with a mean ± SD age and median (IQR) disease duration of 36.76 ± 13.60 years and 6 (2, 9) years, respectively. Patients in the LMV group had more fever, nausea and vomiting, and diarrhea than those in the non-LMV group. They also had more small bowel involvement, bowel wall thickening, target water enhancement signs, mesenteric vessels engorgement and mesenteric fat cloudiness, and higher SLE disease activity. These differences were more pronounced when compared to the surgical AAP group. Treatment with corticosteroids and immunosuppressive drugs gave favorable outcomes in the LMV group. Two of 40 (5.00%) non-LMV AAP patients died, of which 1 (5.26%) was in the surgical AAP group.

Conclusion: LMV was common among SLE patients admitted for AAP. LMV usually presented with fever, gastrointestinal dysmotility symptoms, diffused abdominal pain, together with evidence of active disease. Localized abdominal pain with peritoneal signs favored surgical AAP. Key Points • Lupus mesenteric vasculitis is common among SLE patients presenting with acute abdominal pain. Its presence often associates with gastrointestinal symptoms together with other clinical manifestations of SLE • The signs in abdominal computed tomography findings are not specific and could be observed in other causes of abdominal pain in SLE. Interpretation of these signs should be cautionary and accompanied by history taking and physical abdominal findings • Treatment of lupus mesenteric vasculitis with corticosteroids alone, or in combination with immunosuppressive drugs, usually results in good outcomes.