The management of prolonged fever in low-socioeconomic-status areas by primary care providers such as general practitioners is challenging. Given the endemic nature of many infectious diseases, physicians typically start empirical antibiotic therapy following a limited diagnostic workup including serologic examinations. Herein, we report the case of a young male patient with prolonged fever and arthralgia initially diagnosed with and treated for brucellosis but with a confirmed diagnosis of systemic lupus erythematosus on follow-up. This unique case shows that close follow-up is the best practice for managing prolonged fever in cases with non-specific laboratory findings.