Differential Diagnosis for Peripheral Lymph Node Swelling
Single Most Likely Diagnosis
- Infectious lymphadenitis: This is often the most common cause of peripheral lymph node swelling, typically resulting from bacterial or viral infections. The lymph nodes become enlarged as they work to fight off the infection.
Other Likely Diagnoses
- Reactive lymphadenopathy: This condition occurs in response to a nearby infection or inflammation, not due to the infection itself directly involving the lymph node. It's a common cause of lymph node swelling.
- Lymphoma: Both Hodgkin's and non-Hodgkin's lymphoma can cause peripheral lymph node swelling. Lymphoma is a cancer of the lymphatic system and can present with enlarged lymph nodes.
- Metastatic cancer: Cancer that has spread from another part of the body can cause lymph node swelling. The type of cancer that most commonly metastasizes to lymph nodes varies but includes breast, lung, and melanoma.
Do Not Miss Diagnoses
- Tuberculosis (TB): Although less common in some regions, TB is a critical diagnosis not to miss due to its public health implications and the need for specific treatment. Lymph node swelling can be a presentation of extrapulmonary TB.
- HIV infection: The human immunodeficiency virus can cause persistent generalized lymphadenopathy, especially in the early stages of infection. Missing this diagnosis can have significant implications for the patient's health and public health.
- Cat-scratch disease: Caused by Bartonella henselae, this infection can lead to lymph node swelling, typically after a cat scratch or bite. It's essential to consider in patients with a history of cat exposure.
Rare Diagnoses
- Sarcoidosis: A condition characterized by the growth of granulomas (inflammatory cells) in various parts of the body, including the lymph nodes. It can cause lymph node swelling, although it's less common.
- Kikuchi-Fujimoto disease: A rare, self-limiting condition that causes lymph node swelling, typically in the neck. It's more common in young women and often resolves on its own.
- Castleman disease: A rare disorder that involves an overgrowth of cells in the lymphatic system, leading to lymph node swelling. It can be unicentric (localized) or multicentric (widespread).