Summary of causes and mechanisms of lymphadenopathy1 2 20
| Cause | Mechanism | Examples |
| Infection | Cellular proliferation as a result of antigenic stimulus as a result of a local nodal infection or regional infection | Viral—URTI, EBV, CMV, Rubella, Rubeola, VZV, HSV, Coxsackievirus, HIV Bacterial—Staphylococcus ureus, Group A β-haemolytic streptococcus, anaerobes, diphtheria, cat-scratch disease, tuberculosis, non-tuberculous mycobacterium Protozoa—toxoplasmosis |
| Malignancy | Neoplastic proliferation of inflammatory cells or infiltration of neoplastic cells carried in the lymphatic or haematological circulations | Neuroblastoma, leukaemia, lymphoma, rhabdomyosarcoma |
| Inflammatory | Immune response to antigen or antibodies | Kawasaki disease, juvenile rheumatoid arthritis, systemic lupus erythematosus, serum sickness, dermatopathic adenopathy |
| Drugs | Phenytoin, isoniazid, post DTP immunisation | |
| Other | Rosai-Dorfman disease (benign histocytosis), Kikuchi-Fujimoto disease (necrotising lymphadenitis), storage diseases (infiltration of macrophages filled with metabolite deposits), autoimmune lymphoproliferative syndrome (failure of apoptosis), Castleman’s Disease (lymphoproliferative disorder), progressive transformation of germinal centres |