Lymphadenopathy

Abnormal enlargement of one or more lymph nodes (most regions: >10 mm, inguinal nodes: >15 mm, children: >20 mm), occurring as localized or generalized lymph node enlargement due to infectious, inflammatory, autoimmune, malignant, or reactive processes.

Causes

• Viral infections

  • Common cold

  • Influenza

  • Epstein–Barr virus (EBV)

  • Human immunodeficiency virus (HIV)

  • Cytomegalovirus (CMV)

• Bacterial infections

  • Streptococcal pharyngitis

  • Dental abscess

  • Cellulitis

  • Staphylococcal infections

• Other infectious causes

  • Tuberculosis

  • Tick-borne illnesses

  • Cat-scratch disease

  • Toxoplasmosis

  • Fungal infections

• Autoimmune and inflammatory causes

  • Systemic lupus erythematosus (SLE)

  • Rheumatoid arthritis

  • Sarcoidosis

• Malignant causes

  • Lymphoma

  • Leukemia

  • Metastatic carcinoma

• Reactive causes

  • Routine vaccinations

  • Local tissue injury

  • Drug hypersensitivity reactions

  • Benign reactive lymphoid hyperplasia

• Other causes

  • Storage diseases

  • Castleman disease

  • Kikuchi disease

  • Rosai–Dorfman disease