Differential Diagnosis for Right Lymph Node Swelling in Kids

Single Most Likely Diagnosis

• Reactive lymphadenitis: This is the most common cause of lymph node swelling in children, often due to a viral upper respiratory tract infection. The lymph nodes are typically small (<1cm), mobile, and non-tender, matching the description provided.

Other Likely Diagnoses

• Infectious mononucleosis: Caused by Epstein-Barr virus, it can lead to lymphadenopathy, which may be tender or non-tender. However, the lymph nodes are often larger than 1cm.
• Streptococcal pharyngitis: Although the lymph nodes can be tender, some cases may present with non-tender lymphadenopathy.
• Viral infections (e.g., adenovirus, enterovirus): These can cause lymph node swelling that is usually self-limiting and may not be accompanied by significant tenderness.

Do Not Miss Diagnoses

• Lymphoma: Although rare in children, lymphoma can present with painless lymphadenopathy. It is crucial to monitor the size and characteristics of the lymph nodes over time.
• Tuberculosis: Can cause lymph node swelling that is often non-tender. A thorough history, including exposure risks and travel, is essential.
• Cat-scratch disease: Caused by Bartonella henselae, transmitted through cat scratches. It typically causes a single, painful lymph node, but the pain may be mild or absent in some cases.

Rare Diagnoses

• Kawasaki disease: An acute febrile illness that can cause lymphadenopathy, among other symptoms like rash, conjunctivitis, and changes to the lips and oral cavity.
• Sarcoidosis: A rare condition in children that can cause lymphadenopathy, often accompanied by other systemic symptoms.
• Leukemia: Although very rare, leukemia can cause lymph node swelling. Other signs like pallor, fatigue, or petechiae might be present.

Each of these diagnoses has a different set of implications for treatment and prognosis, emphasizing the importance of a thorough evaluation and follow-up.