Sarcoidosis. A rare differential diagnosis of interstitial nephritis and uveitis

We report the case of a 13-year-old boy who presented with impaired exercise tolerance, loss of weight and fever. Laboratory data indicated systemic inflammation and renal failure suggestive of tubular dysfunction. A kidney biopsy showed epithelioid granulomatous tubulointerstitial nephritis. The boy developed granulomatous uveitis during follow-up. TINU syndrome (tubulointerstitial nephritis and uveitis) was diagnosed and sarcoidosis was considered to be the most probable cause. Treatment was started with prednisone and methotrexate and renal function completely recovered, whereas after 2 years of treatment the uveitis is still mildly active. Sarcoidosis is a rare disease of childhood; nevertheless it must be considered in the differential diagnosis of granulomatous uveitis and tubulointerstitial nephritis.