Differential Diagnosis for a 2cm Tender Right Inguinal Lymph Node
Single Most Likely Diagnosis
- Inguinal lymphadenitis due to a skin infection: This is the most likely diagnosis, as the inguinal lymph nodes are commonly involved in infections of the lower extremities, genitalia, or perineal area. The tenderness of the lymph node supports an infectious or inflammatory cause.
Other Likely Diagnoses
- Sexually Transmitted Infection (STI): Given the location of the lymph node, an STI such as syphilis, herpes simplex, or chlamydia could be a likely cause, especially if the patient has been sexually active without proper protection.
- Folliculitis or Furunculosis: These are skin infections that can cause lymphadenopathy, particularly if they are located in the drainage area of the inguinal lymph nodes.
- Cellulitis: An infection of the skin and subcutaneous tissue, which can cause tender lymphadenopathy.
Do Not Miss Diagnoses
- Malignancy (Lymphoma or Metastatic Cancer): Although less likely, it is crucial not to miss a diagnosis of lymphoma or metastatic cancer to the lymph node, as these conditions require prompt and specific treatment. A biopsy may be necessary for diagnosis.
- Tuberculosis: TB can cause lymphadenitis, and although it is less common in some regions, it is a critical diagnosis not to miss due to its public health implications and the need for specific treatment.
- HIV: Inguinal lymphadenopathy can be an early sign of HIV infection, making it a "do not miss" diagnosis due to the importance of early treatment and management.
Rare Diagnoses
- Cat-Scratch Disease: Caused by Bartonella henselae, this infection can lead to lymphadenopathy, typically after a cat scratch or bite.
- Toxoplasmosis: A parasitic infection that can cause lymphadenopathy, although it is more commonly associated with cervical lymph nodes.
- Kikuchi Disease: A rare form of lymphadenitis that is more common in Asian populations and can present with tender lymph nodes, fever, and night sweats.