Systemic lupus erythematosus complicated by Crohn’s disease: a case report and literature review

BACKGROUND Although patients with systemic lupus erythematosus (SLE) may experience various gastrointestinal disorders, SLE and Crohn's disease (CD) rarely coexist. The diseases may have gastrointestinal (GI) manifestations, laboratory results, and radiographic findings that appear similar and consequently differentiating between GI involvement in CD and in SLE may be difficult. We present the case of a patient with SLE and CD who developed continuous GI bleeding and diarrhea that was initially treated as SLE-related colitis to little effect. CASE PRESENTATION A 55-year-old Japanese woman with systemic lupus erythematosus (SLE) developed continuous gastrointestinal bleeding and diarrhea since the patient was aged 30 years that was initially treated as SLE-related colitis. Although a longitudinal ulcer and aphthous ulcers in the colon were observed every examination, biopsy showed only mild inflammation and revealed neither granuloma nor crypt abscess. The patient underwent surgery for anal fistulas twice at 50 and 54 years of age and her symptoms were atypical of lupus enteritis. Colonoscopy was performed again when the patient was 55 years of age because we suspected she had some type of inflammatory bowel disease (IBD). Cobblestone-like inflammatory polyps and many longitudinal ulcers were detected between the descending colon and the cecum. Macroscopic examination strongly suggested CD. Histopathological examination revealed non-caseating granuloma and no evidence of vasculitis, consistent with CD. Introduction of infliximab dramatically relieved the patient's melena and abdominal symptoms. CONCLUSION Diagnostic criteria for CD and SLE overlap, making them difficult to diagnose correctly. It is important to consider CD for patients who have SLE with gastrointestinal manifestations. The pathology of lupus enteritis should be clarified through the accumulation of cases of SLE combined with CD.