How does acute hemarthrosis present in a patient with hemophilia?
Hemophilia A (factor VIII deficiency) and hemophilia B (factor IX deficiency) are associated with hemarthrosis. Prodromal symptoms of stiffness or warmth occur in the affected joint. As the joint capsule distends, severe pain follows with swelling from effusion and decreased range of motion. The swelling will eventually tamponade the bleeding and the hemarthrosis will gradually resolve over days to weeks. Almost all patients with severe hemophilia (<1% of normal factor activity) and half of patients with moderate disease (1%–5% factor activity) will have recurrent hemarthroses spontaneously or following minor trauma. Large joints (knees, elbows, ankles) are most commonly involved. If factor levels are >5% of normal, hemarthroses tend to be less frequent or occur following more significant trauma. Hemarthroses often first begin to occur in weight-bearing joints when a child is just learning to walk.
