Two Cases of Human Immunodeficiency Virus Infection Mimicking Rheumatic Disease with a Literature Review

Human immunodeficiency virus (HIV) causes immunodeficiency by infecting and destroying CD4-positive T cells. However, HIV infection has also been reported to manifest with rheumatic-like symptoms, making differential diagnosis from rheumatic diseases important in clinical practice. In this report, we present two cases in which HIV infection was identified after an initial diagnosis of a rheumatic disease. Case 1: The patient was initially diagnosed as having Behçet's disease based on a history of recurrent oral ulcers and HLA-B51 positivity, but subsequently developed recurrent diarrhea episodes and gastrointestinal ulcers. Further investigation revealed the diagnosis of HIV infection. Case 2: The patient was diagnosed as having systemic lupus erythematosus based on the presence of facial erythema, cytopenias, and seropositivity for antinuclear and anti-double-stranded DNA antibodies. He subsequently developed fever and weight loss, and further examination led to the diagnosis of HIV infection. In both cases, clinical improvement was achieved with antiretroviral therapy and treatment of concomitant infections. These cases highlight the importance of recognizing that HIV infection can mimic rheumatic diseases. HIV screening should be considered in cases where clinical features are atypical or there is insufficient response to conventional treatments.