bubble_chart Overview

Infectious Mononucleosis is caused by the Epstein-Barr (E-B) virus. This virus is morphologically similar to the herpes virus and is characterized by irregular fever, pharyngitis, lymphadenopathy, splenomegaly, lymphocytosis with atypical lymphocytes, and the presence of heterophile antibodies in the blood.

bubble_chart Etiology

This condition is caused by the Epstein-Barr virus, which resembles the herpes virus in morphology and was initially discovered in the culture of Burkitt's lymphoma cells. This virus can only grow and proliferate in lymphoma cells or peripheral blood lymphoid cell cultures. It cannot proliferate in virus-sensitive cells. This condition may be transmitted through direct contact and droplets.

bubble_chart Clinical Manifestations

It commonly occurs in children and young adults. The incubation period is 33-39 days in adults and about 10 days in children. The onset is slow. Prodromal symptoms such as headache and lack of strength are often present. The fever is irregular, ranging from mild fever to high fever, with body temperature reaching 40-41°C. The fever pattern can be irregular or continuous and may persist for more than 2 weeks. A few cases may not have fever. It is often accompanied by shivering, muscle aches, or profuse sweating. A few days after the onset, pharyngitis appears, manifesting as diffuse membranous tonsillitis, with possible bleeding points at the junction of the soft and hard palate. Lymphadenopathy is seen in about 70% of cases, with lymph nodes throughout the body being affected, mainly in the neck, followed by the axillary and inguinal regions. The lymph nodes are of medium hardness, non-tender, non-adherent, and do not suppurate, and they subside slowly. About 50% of cases have grade II splenomegaly. The liver may also be affected. A few cases may present with symptoms of the nervous system, nephritis, pneumonia, myocarditis, and purpura.

Approximately 10-15% of patients develop a rash 4-6 days after the onset, typically presenting as macules and papules, maculopapular rash, measles-like rash, urticaria-like rash, and scarlet fever-like rash. The rash is distributed on the trunk, upper limbs, face, forearms, and lower limbs. The rash usually subsides within a few days. The course of the disease lasts for several weeks and can recur. Some suggest that the chronic form of the disease can last from 3 months to 4 years.

bubble_chart Auxiliary Examination

1. Blood Picture: Grade I increase in white blood cells, early increase in neutrophils, significant increase in monocytes, usually accounting for 40-80%, even up to 90%, presence of abnormal lymphocytes (more than 10%) which are larger than lymphocytes and resemble monocytes, these cells may be abnormal young lymphocytes.

2. Serum Test: The heterophil agglutination test (Paul-Bunnell) has a high positive rate of up to 60%, increasing by more than 10% in the second week, and lasting for 4-6 weeks or longer.

3. Fluorescent Antibody Test: Presence of E-B virus antibodies.

4. Histopathology: Widespread lymphoid tissue hyperplasia and focal monocytic infiltration in the systemic mononuclear phagocyte system and other organs.

bubble_chart Diagnosis

Based on fever, membranous tonsillitis, generalized lymphadenopathy, hepatosplenomegaly, and rash, the presence of petechiae in the pharynx and palate is highly diagnostic. Blood count: 10% or more atypical lymphocytes. The heterophile agglutination test is positive, reaching 60% in the first week and increasing by another 10% in the second week. The presence of EB virus antibodies makes the diagnosis straightforward.

bubble_chart Treatment Measures

Immediately isolate any discovered patients. There is currently no specific treatment available. Only symptomatic treatment is provided. Intramuscular injection of 30-300mL of convalescent serum can yield therapeutic effects. For complications such as encephalitis, myocarditis, autoimmune hemolytic anemia, or thrombocytopenic purpura, corticosteroids may be used. Some also believe that chloroquine is effective for severe cases.

bubble_chart Differentiation

This disease needs to be differentiated from pharyngitis, tonsillitis, subcutaneous nodular lymphadenopathy, cold-damage disease, maculopapular cold-damage disease, hepatitis, and lymphocytic leukemia.