Medical complications of infectious mononucleosis.

Infectious mononucleosis is usually a benign, self-limited disease, but complications may develop in up to 5 percent of patients. The complications can be life-threatening and may precede, follow or coincide with the usual symptoms of infectious mononucleosis. Occasionally, a complication is the only clinical manifestation of the disease. Complications may be due to an autoimmune response, a lymphocytic infiltrative reaction, generalized edema of the airway tissues or enlargement of the spleen.