Infectious mononucleosis (IM; also known as EBV infectious mononucleosis or glandular fever or Pfeiffer's disease or Filatov's disease and sometimes colloquially as the kissing disease from its oral transmission or simply as mono in North America and as glandular fever in other English-speaking countries). It is an infectious, widespread viral disease caused by the Epstein-Barr virus (EBV), one type of herpes virus, to which more than 90% of adults have been exposed. Most people are exposed to the virus as children, when the disease produces no noticeable symptoms or only flu-like symptoms. In developing countries, people are exposed to the virus in early childhood more often than in developed countries. As a result, the disease in its observable form is more common in developed countries. It is most common among adolescents and young adults. 
Especially in adolescents and young adults, the disease is characterized by fever, sore throat and fatigue, along with several other possible signs and symptoms. It is primarily diagnosed by observation of symptoms, but suspicion can be confirmed by several diagnostic tests.
The syndrome was described as an infectious process by Nil Filatov in 1887 and independently by Emil Pfeiffer in 1889.
Signs and symptoms
The classical symptoms of mononucleosis are a sore throat, fever, fatigue, weight loss, malaise, pharyngeal inflammation, 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). Often, if symptoms are not apparent in the first two days of possible viral infection, then mononucleosis is not present. 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.
Full article ▸