Infective Endocarditis Mimicking Reactive Arthritis

BACKGROUND: Infective endocarditis (IE) in young adults can present with nonspecific symptoms mimicking alternative diagnoses. CASE SUMMARY: A 29-year-old man presented to the emergency department with erythematous, pruritic papules on his shins and ankles with bilateral knee pain and swelling. After the initial work-up for septic or inflammatory arthritis, he was empirically treated for reactive arthritis with systemic steroids. A month later, he re-presented with headache, dark urine, and unintentional 40-lb weight loss. Imaging revealed multiple ischemic strokes in the bilateral cerebelli and right thalamus. He received a diagnosis of Streptococcus mitis endocarditis with severe aortic regurgitation and septic brain emboli, underwent mechanical aortic valve replacement, and was treated for 4 weeks with antibiotics. DISCUSSION: Nonspecific symptoms of IE can delay diagnosis and risk complications, including stroke and valvular destruction. Reactive arthritis should remain a diagnosis of exclusion. TAKE-HOME MESSAGE: Maintain suspicion for IE in patients with unexplained systemic inflammation and arthralgias.