Infectious Mononucleosis

Infectious mononucleosis is a lymphoproliferative disease, benign and resolve spontaneously, which is caused by the Epstein-Barr virus (EBV). Clinical presentation and severity of infectious mononucleosis is a variable, a typical case starts with chills, fever, malaise, enlarged lymph nodes painful cervical and intense pharyngitis. In the pharynx and tonsillar exudate cream can be observed, and just under 50% of the cases are petechiae on the ceiling. In 10 to 15% of patients fine spotted rash of rubella warned. Splenomegaly is characteristic and can cause pain in the left upper quadrant of the abdomen. For diagnosis is important that there is a lymphocytosis and identified in the peripheral blood smear atypical lymphocytes. Most patients have heterophile antibodies that agglutinate sheep erythrocytes in the Paul-Bunnell test.

Pathology
The main changes affecting infectious mononucleosis blood, lymph nodes, spleen, liver, central nervous system, and, sometimes, other organs. In peripheral blood lymphocytosis no absolute total leukocyte number between 12,000 and 18.000/mm3. Many of the large atypical lymphocytes, from 12 to 16 microns in diameter, characterized by abundant cytoplasm and vacuoles containing many clear oval nucleus, notched or withdrawn. These atypical lymphocytes, which have largely T cell markers are usually unique enough to allow diagnosis by examination of peripheral blood smears.

Lymph nodes are typically modest growth throughout the body, especially in the posterior cervical, axillary and inguinal. On histologic examination, lymphoid tissue is flooded with atypical lymphocytes occupied by cortical areas (T-cell).

Etiology
Epstein-Barr virus that causes infectious mononucleosis is the same herpes virus that can cause severe and subclinical Burkitt lymphoma affects 50% of the world population.

Prognosis
 It is good to excellent, with a slow but progressive improvement after two to four weeks of fever. Deaths are rare and usually breaks atribuilbles against recurrent infections or spleen.