Differential Diagnosis for Unilateral Lymphadenopathy
Single Most Likely Diagnosis
- Infectious lymphadenitis: This is often the most common cause of unilateral lymphadenopathy, typically resulting from bacterial or viral infections. The lymph nodes become enlarged as they fight off the infection.
Other Likely Diagnoses
- Cat scratch disease: Caused by Bartonella henselae, this condition often presents with unilateral lymphadenopathy, typically in the axillary or neck region, following a cat scratch or bite.
- Tuberculosis: Although less common in some regions, tuberculosis can cause unilateral lymphadenopathy, especially in the cervical or supraclavicular regions.
- Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with unilateral lymphadenopathy, although it's more commonly associated with systemic symptoms.
Do Not Miss Diagnoses
- Malignancy (e.g., metastatic cancer): It's crucial not to miss a diagnosis of cancer, such as lymphoma or metastasis to lymph nodes from another primary site, as timely treatment significantly affects outcomes.
- HIV infection: Acute HIV infection can present with lymphadenopathy, and missing this diagnosis could lead to delayed treatment and significant health consequences.
- Sarcoidosis: Although often presenting with systemic symptoms, sarcoidosis can sometimes cause isolated lymphadenopathy, and missing this diagnosis could lead to unnecessary treatments or delayed diagnosis of a potentially serious condition.
Rare Diagnoses
- Kikuchi disease: A rare form of lymphadenitis, more common in young women, characterized by cervical lymphadenopathy and fever.
- Kimura disease: A rare, chronic inflammatory disorder that typically presents with lymphadenopathy and eosinophilia, more common in Asian males.
- Castleman disease: A rare disorder that can cause lymphadenopathy, often presenting with systemic symptoms, but can be asymptomatic in its localized form.
Each of these diagnoses has distinct characteristics and implications for patient care, emphasizing the importance of a thorough diagnostic workup for unilateral lymphadenopathy.