Differential Diagnosis for a 10-year-old with Tender Swollen Posterior Cervical Lymph Node

• Single most likely diagnosis:
  • Viral pharyngitis or upper respiratory infection: This is the most common cause of tender and swollen lymph nodes in the cervical region in children, often accompanied by some neck pain and usually resolves on its own.
• Other Likely diagnoses:
  • Bacterial pharyngitis (e.g., streptococcal infection): Similar to viral pharyngitis but may require antibiotic treatment. Symptoms can include sore throat, fever, and swollen lymph nodes.
  • Reactive lymphadenitis: This condition occurs as a reaction to an infection elsewhere in the body, not necessarily in the lymph node itself, and can cause lymph node swelling and tenderness.
  • Mononucleosis (infectious mononucleosis): Caused by Epstein-Barr virus, it can lead to swollen lymph nodes, fever, and sore throat, although it's more common in adolescents and young adults.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed):
  • Lymphoma: Although rare in children, lymphoma can present with swollen lymph nodes, and early diagnosis is crucial for effective treatment.
  • Tuberculosis (TB): Can cause lymphadenitis, especially in the cervical region, and is critical to diagnose due to its potential for serious complications if left untreated.
  • Cat-scratch disease: Caused by Bartonella henselae, transmitted through cat scratches, and can lead to swollen and painful lymph nodes, usually with a history of cat exposure.
• Rare diagnoses:
  • Kawasaki disease: An acute febrile illness that can cause lymph node swelling among other symptoms like fever, rash, and conjunctivitis, primarily affecting children under five but can occur in older children.
  • Toxoplasmosis: A parasitic infection that can cause lymphadenopathy, although it's more commonly associated with other systemic symptoms.
  • Cystic hygroma or other congenital lymphatic malformations: These are rare conditions that can present with neck masses, though they are typically identified earlier in life.
  • Leukemia: Although very rare, certain types of leukemia can present with lymphadenopathy, and given the severity of the disease, it's essential to consider it in the differential diagnosis.