PO:11:167 | Subtle symptoms masking a challenging diagnosis: a clinical case of intestinal vasculitis in systemic lupus erythematosus

Ilaria Pace¹, Giulia Rizzo¹, Elisabetta Chessa², Davide Corradini¹, Roberta Origa¹, Valentina Ibba², Alberto Floris^1|2, Alberto Cauli^1|2, Matteo Piga^1|2 | ¹Sapienza Università di Roma; ²SC Reumatologia, AOU Cagliari, Cagliari, Italy 

Background. Lupus enteritis is a rare but potentially life-threatening manifestation of systemic lupus erythematosus (SLE). This report highlights the importance of early diagnosis and prompt treatment, by describing a case of SLE complicated by intestinal involvement, initially presenting with nonspecific symptoms.

Materials and Methods. A 59-year-old woman with Sjögren’s syndrome (diagnosed in 2021), intolerant to disease modifying antirheumatic drugs (DMARDs) and with urticarial–angioedema reactions to NSAIDs, paracetamol, antibiotics and glucocorticoids (GCs), was first admitted in November 2024 to the Internal Medicine Unit for abdominal pain, diarrhea, vomiting and fever. Contrast-enhanced abdominal computed tomography (ceCT) revealed a right common iliac artery dissection and a penetrating aortic ulcer. In the absence of surgical indication, she was discharged with a diagnosis of viral gastroenteritis and started empirical antibiotics and anti-platelets. Due to persistent fever, periorbital edema and hypocomplementemia, she was transferred to our Rheumatology Unit. On admission, she had fever, purpura on the lower limbs, diffuse alopecia and erythematous–pomphoid lesions on the chest and trunk. Laboratory tests showed hemoglobin 9.2 g/dL, CRP 14 mg/L (normal values <5), ESR 49 mm/h, ANA 1:640 (granular pattern), anti-SSA/SSB positive, anti-dsDNA negative, direct Coombs test positive, C3 45 mg/dL (nv<90), C4 4 mg/dL (nv<12), hypergammaglobulinemia (27.2%). During hospitalization, she developed recurrent urticaria–angioedema episodes unrelated to drug exposure: allergologic evaluation suggested Urticaria–Angioedema Syndrome (normal C1q inhibitor). She was diagnosed with “SLE and Urticaria–Angioedema Syndrome” (SLEDAI=15, Physician Global Assessment [PGA]=1.5), and treated with GCs pulses, azathioprine and omalizumab. In January 2025, she was readmitted for palatal petechiae, urticarial lesions on face and trunk, periorbital edema and palpable purpura on the lower limbs. Worsening fever (up to 39.4°C), diarrhea with hematochezia and vomiting prompted review of the previous ceCT, revealing trilaminar thickening of two-thirds of the small intestine compatible with the “target sign” and mesenteric stranding due to lymphatic–vascular congestion (Figure 1A).

Results. Clinical and radiological findings were consistent with lupus enteritis (SLEDAI=15, PGA=2.5). She was treated with GCs pulses and cyclophosphamide (Cyc) 500 mg (Eurolupus protocol). After the second Cyc infusion, fever, diarrhea and urticarial lesions resolved. Follow-up CT enterography confirmed complete resolution of the intestinal involvement (Figure 1B). For the persistence of purpura on the lower limbs (SLEDAI=12, PGA=1.1), in April she started rituximab and hydroxychloroquine, followed by mycophenolate mofetil as maintenance, achieving in September 2025 complete remission (SLEDAI=0, PGA=0).

Conclusions. This case highlights how nonspecific symptoms may conceal severe disease manifestations, delaying diagnosis and treatment. Therefore, early recognition and strong induction therapy are crucial to achieve disease control, prevent organ damage and avoid potentially fatal complications.