CASE PRESENTATION
A 40-year-old male with no prior medical history was hospitalized for 7 days due to (R) knee pain and swelling. Fever has been around for the past two weeks, coming and going. The discomfort made it impossible for him to walk. There were no gastrointestinal or genitourinary symptoms. As well as unremarkable cardiopulmonary and neurological review. No other joint involvement. No skin rashes and There was no history of trauma. The patient stated that he had a similar episode of knee pain 10 years ago. He denied any contact with animals and no history of raw milk consumption. His temperature was 37.8°C. The (R) knee was swollen, hot, and tender with a limited range of movement (Figure1). The deferential diagnosis included septic arthritis and crystal-induced arthritis. The general examination was normal. Laboratory investigation showed White Blood Count (WBC) of 5.2 and C-Reactive Protein (CRP) was high 110. Hemoglobin (Hb) was 12.9, mean corpuscular volume (MCV) 60.9; red blood cell distribution width (RDW) was 18.6, suggestive of iron deficiency anemia. Platelets were normal at 270. The coagulation profile showed high Prothrombin Time (PT) 12.8, international normalized ratio (INR), and partial thromboplastin time (PTT) were normal. Blood chemistry investigations were all normal. Brucella serology was done, which showed Brucella IgG was positive 1: 320, and IgM was negative. Synovial fluid aspirate revealed yellow, turbid fluid with WBCs of 4,800, red blood cells (RBCs) 13,475, neutrophils 31.0, lymphocytes 2.0, and monocytes 67. Brucella melitensis was detected in both blood cultures and synovial fluid. The echocardiogram did not reveal vegetation. Right knee soft tissue ultrasound revealed large joint effusion reaching suprapatellar bursa associated with synovial irregular thickening and hypervascularity (Figure 2). The largest collection measuring 8.1x2.2 cm. Rifampicin, doxycycline, and gentamycin were started, and his condition has improved.