Idiopathic eosinophilic synovitis of the knee joint with peripheral eosinophilia - a rare case report.

Synovitis, presenting as a synovial effusion is common. The most common cause include tuberculosis, osteoarthritis. Here with, presenting a rare case of monoarticular synovitis with synovial fluid and peripheral blood eosinophilia of unknown aetiology in an 18-year-old male. We review the clinical and pathological features and impress the need for synovial fluid examination in all cases.