Case Presentation: A 32-year-old woman presented with progressively worsening abdominal distention for weeks associated with abdominal pain, postprandial nausea and emesis. The physical exam was notable for generalized tenderness and fluid wave. Lab work revealed proteinuria, acute kidney injury, normocytic anemia, and leukocytosis. She had undergone a diagnostic paracentesis at an outside hospital that had showed serum-ascites albumin gradient of 0.6 indicating lack of portal hypertension. There was no evidence suggesting the common causes of low SAAG ascites including peritoneal malignancies, mycobacterium tuberculosis, and nephrotic syndrome. Upon further investigation, she reported chronic pain in bilateral wrists and knees with morning stiffness and occasional swelling. She also endorsed hair loss, dry mouth, dry eyes, and Raynaud’s phenomenon. A rheumatological disorder was suspected; Antinuclear antibody (ANA), double-stranded deoxyribonucleic acid(ds-DNA) anti-ribonucleoprotein (RNP), anti-Ro, and anti-La antibodies all came back markedly positive. Rheumatology was consulted for systemic lupus erythematosus (SLE) and the ascites was thought to be from lupus serositis. Intravenous (IV) methylprednisolone 48 mg daily was commenced resulting in significant improvement in her ascites. Patient was discharged on methylprednisolone 32 mg daily and hydroxychloroquine 200 mg daily to follow up with rheumatology as an outpatient.
Discussion: SLE is an autoimmune disease characterized by a widespread loss of self-tolerance and consequently multiorgan inflammation caused by genetic factors, endocrine, environmental triggers, and aberrant innate immune responses. This case exemplifies the diagnostic challenge posed to clinicians when patients do not present with typical symptoms resulting in delay in appropriate diagnosis and care. These typical symptoms include fatigue, fever, malar rash, and arthralgias.In our case, the presenting symptom was ascites caused by lupus serositis, which is a diagnosis of exclusion. Ascites occurs in only 10% of patients with lupus, and can be secondary to peritoneal serositis, protein-losing enteropathy, nephrotic syndrome, or constrictive pericarditis. Lupus serositis commonly affects the pleural and pericardium, and rarely the peritoneum. Lupus serositis is a type III hypersensitivity reaction where immune complexes deposit on serosal surfaces, triggering complement activation. This initiates an inflammatory cascade, producing pro-inflammatory mediators (C3a, C5a, C5b-9) and cytokines (TNF-α, IL-1, IL-6). Consequently, neutrophils and other immune cells are recruited, enhancing inflammation and leading to tissue injury and fluid accumulation in serous cavities. Peritoneal inflammation leads to abdominal pain and ascites, as in our patient.
Conclusions: Atypical presentations in SLE constitute a diagnostic dilemma for physicians due to the wide range of clinical manifestations of the disease, however, a detailed history and a high index of suspicion can help with appropriate diagnosis. Even though ascites is not included in the official classification criteria of SLE, it should be considered for patients with an unclear etiology of ascites in addition to the classic lupus symptoms.