Acute lymphadenitis(acute infection of lymph nodes)is usually caused by microbes transported in lymph from other areas of infection. The nodes become inflamed,enlarged and congested with blood,and chemotaxis attracts large numbers of phagocytes. If lymph nodes defends(phagocytes and antibody production) are overwhelmed,the infection can cause abscess formation within the node. Adjacent tissues may become involved,and infected materials transported through other nodes and into the blood.
Acute lymphadenitis is secondary to a number of conditions:
- Infectious mononucleosis(glandular fever).
This is a highly contagious viral infection,usually of young adults,spread by direct contact. During the incubation period,viruses multiply in the epithelial cells of the pharynx. They subsequently spread to cervical lymph nodes,then to lymphoid tissue throughout the body.
Clinical features include tonsillitis,lymphadenopathy and splenomegaly. A common complication is myagic encephalitis.
2.Other diseases.
Minor lymphadenitis accompanies many infections and indicates the mobilisation of normal protective mechanisms,eg.proliferation of defence cells. More serious infection occurs in,eg. measles,typhoid and wound or skin infections. Chronic lymphadenitis occurs following unresolved acute infections,in tuberculosis,syphillis and some low-grade infections.
