[The differential diagnosis of hemarthrosis--septic arthritis in patients with hemophilia].

A 12-year-old boy with severe hemophilia A fell ill with high fever and painful swelling of joints. There was a delay of four days in the diagnosis of septic arthritis. The course of the disease shows some important distinguishing criteria, speaking in favour of septic arthritis: 1. longlasting temperature above 39 degree C; 2. an elevated peripheral leukocyte count; 3. increasing complaints despite normalisation of the coagulation defect.