Crohn disease is an inflammatory bowel disease that involves any region of the alimentary tract from the mouth to the anus and it is transmural. Children with early onset are more likely to have colonic involvement. Infliximab constitutes today one of major therapeutic approaches in severe and fistulising cases of Crohn disease. We present the case of a 16 year-old boy who was admitted to our department presenting recto-scrotal fistula, fever, tenesmus, red-bloody stools, pain during and after defecation. In order to induce remission of the disease, we administrated Infliximab. The initial response to therapy was good, but he developed an acute infusion reaction during the administration of the 3rd dose, which forced us to quit this therapy.