Infectious Mononucleosis - Signs and Symptoms

Signs and Symptoms

The classic symptoms of mononucleosis are a sore throat, fever, fatigue, malaise, pharyngeal inflammation, vomiting, petechiae and loss of appetite. Common signs include lymphadenopathy (enlarged lymph nodes), splenomegaly (enlarged spleen), hepatitis (refers to inflammation of hepatocytes—cells in the liver) and hemolysis (the bursting of red blood cells). Older adults are less likely to have a sore throat or lymphadenopathy, but are instead more likely to present with hepatomegaly (enlargement of the liver) and jaundice. Rarer signs and symptoms include thrombocytopenia (lower levels of platelets), with or without pancytopenia (lower levels of all types of blood cells), splenic rupture, splenic hemorrhage, upper airway obstruction, pericarditis and pneumonitis. Another rare manifestation of mononucleosis is erythema multiforme.

Mononucleosis is sometimes accompanied by secondary cold agglutinin disease, an autoimmune disease in which abnormal circulating antibodies directed against red blood cells can lead to a form of autoimmune hemolytic anemia. The cold agglutinin detected is of anti-i specificity. Patients with infectious mononucleosis are sometimes misdiagnosed with a streptococcal pharyngitis (because of the classical clinical triad of fever, pharyngitis and adenopathy) and are given antibiotics such as ampicillin or amoxicillin as treatment. Some studies indicate about 80–90% of patients with acute Epstein–Barr virus infection treated with such antibiotics develop a red, diffuse rash.