Differential Diagnosis for Lymphadenopathy in the Neck (Single Lymph Node)
Single Most Likely Diagnosis
- Reactive Lymphadenitis: This is the most common cause of lymphadenopathy in the neck, often resulting from a viral upper respiratory infection. The lymph node enlargement is usually self-limiting and resolves without specific treatment.
Other Likely Diagnoses
- Tuberculosis (TB): TB can cause lymphadenopathy, especially in the neck, and is more common in individuals from endemic areas or with compromised immune systems. Diagnosis is made through a combination of clinical findings, imaging, and microbiological tests.
- Toxoplasmosis: This parasitic infection can cause lymphadenopathy, particularly in immunocompetent individuals. It's often diagnosed based on serological tests.
- Cat-Scratch Disease: Caused by Bartonella henselae, this condition typically presents with lymphadenopathy near the site of a cat scratch or bite. Diagnosis is often clinical, supported by serology.
Do Not Miss Diagnoses
- Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with lymphadenopathy in the neck. Early diagnosis is crucial for effective treatment, making it a "do not miss" diagnosis.
- Metastatic Cancer: Various cancers, such as squamous cell carcinoma of the head and neck, can metastasize to lymph nodes in the neck. A thorough examination and imaging studies are essential for diagnosis.
- HIV Infection: Acute HIV infection can cause lymphadenopathy, and diagnosing HIV early is critical for managing the disease and preventing transmission.
Rare Diagnoses
- Sarcoidosis: This autoimmune disease can cause lymphadenopathy, among other symptoms, but it's less common than other causes. Diagnosis involves clinical findings, imaging, and histological confirmation.
- Kikuchi-Fujimoto Disease: A rare, self-limiting condition that causes lymphadenopathy, typically in young women. Diagnosis is made through lymph node biopsy.
- Kimura Disease: A chronic inflammatory disorder that can cause lymphadenopathy and is more common in Asian males. Diagnosis is based on clinical and histopathological findings.