By- Dr. Armaan Singh

Inflammation as a cause of lymph node enlargement is known as lymphadenitis.  In practice, the distinction between lymphadenopathy and lymphadenitis is rarely made. Inflammation of the lymphatic vessels is also known aslymphangitis.Infectious lymphadenitides affecting lymph nodes in the neck are often called scrofula.

Types

*Localized lymphadenopathy: due to localized spot of infection e.g., an infected spot on the scalp will cause lymph nodes in the neck on that same side to swell up

*Generalized lymphadenopathy: due to a systemic infection of the body e.g., influenza or secondary syphilis

*Persistent generalized lymphadenopathy (PGL): persisting for a long time, possibly without an apparent cause

*Dermatopathic lymphadenopathy: lymphadenopathy associated with skin disease.

*The most distinctive sign of bubonic plague is extreme swelling of one or more lymph nodes that bulge out of the skin as "buboes." The buboes often become necrotic and may even rupture.

*Infectious mononucleosis is an acute viral infection caused by Epstein-Barr virus and may be characterized by a marked enlargement of the cervical lymph nodes.

*It is also a sign of cutaneous anthrax  and Human African trypanosomiasis

*Toxoplasmosis, a parasitic disease, gives a generalized lymphadenopathy (Piringer-Kuchinka lymphadenopathy).

*Plasma cell variant of Castleman's disease - associated with HHV-8 infection and HIV infection

*Mesenteric lymphadenitis after viral systemic infection (particularly in the GALT in the appendix) can commonly present like appendicitis.

DIFFERENTIAL DIAGNOSES*Acute Lymphoblastic Leukemia*Acute Myelocytic Leukemia*Cystic Fibrosis*Gaucher Disease*Histiocytosis*Hodgkin Disease*Human Immunodeficiency Virus *Kawasaki Disease*Measles*Mononucleosis and Epstein-Barr Virus Infection*Neuroblastoma*Plague*Rubella*Serum Sickness*Streptococcal Infection, Group A*Syphilis*Systemic Lupus Erythematosus*Taenia Infection*Tuberculosis