A Not-so-sports-related Cause Of Joint Pain

HISTORY: A 42-year-old male with no significant past medical history presented to the emergency room complaining of acute onset right forehead pain, swelling/pain of the right elbow, and right knee pain associated with decreased hearing on the right. Denied trauma or injury. He also reported 2 weeks of daily bloody bowel movements which resolved spontaneously a few weeks prior. Maternal history of lupus. Admits to 2-3 tequila drinks every other day, and 1 new sexual partner. The patient was admitted after initiation of intravenous antibiotics and orthopedics consulted for synovial joint aspiration. Surgery was consulted during admission for temporal artery biopsy. PHYSICAL EXAMINATION: Afebrile. Mild right temporal swelling and tenderness. Mild-moderate right elbow swelling, erythema, and tenderness with decreased range of motion secondary to pain. Right knee medial joint tenderness without swelling or erythema. DIFFERENTIAL DIAGNOSIS:- Reactive arthritis- Gout- Septic arthritis- Giant cell arteritis-induced arthropathy- Peripheral arthritis secondary to inflammatory bowel disease- Systemic lupus erythematosus or other autoimmune process. TEST AND RESULTS: Elevated inflammatory markersRight elbow radiographs: fat pad elevation implying joint effusionRight knee radiographs: no abnormalitySynovial fluid aspirate: 95% neutrophils with 9479 total nucleated cell count, non-purulent and without crystals; no growth on cultureHIV, chlamydia, and gonorrhea screening negativeANA negativeRight temporal artery biopsy: focal disruption of elastic lamella, focal intraluminal acute thrombus, and minimal inflammation. FINAL/WORKING DIAGNOSIS: Initial discharge diagnosis: Giant cell arteritis. TREATMENT AND OUTCOMES:- Ceftriaxone and vancomycin for possible septic arthritis discontinued after return of synovial fluid- Prednisone 60 mg course with taper initiated inpatient- Joint pain symptoms mostly resolved prior to discharge- Outpatient rheumatologist and pathologist are not convinced of pathologic findings. Believe presentation is most suggestive of reactive arthritis secondary to enteric infection or peripheral arthritis secondary to inflammatory bowel disease- Further autoimmune workup and gastroenterology follow up pending