A Rare Presentation of Systemic Lupus Erythematosus in a Patient With Fever of Unknown Origin

This case presents a 23-year-old male with a rare presentation of lupus as fever of unknown origin (FUO). The patient's clinical symptoms, examination findings, and laboratory results painted a complex picture that necessitated considering macrophage activation syndrome and adult-onset Still's disease but ultimately led to the diagnosis of systemic lupus erythematosus. The case emphasizes the importance of including lupus in the differential diagnosis of FUO given the associated risks and higher mortality rates in this demographic, especially in males. Understanding lupus prevalence and classification criteria aids in diagnosis, highlighting the importance of a systematic approach for FUO and emphasizing timely intervention for improved patient outcomes.