Differential Diagnosis for a 50-year-old with Swelling on the Right Side of the Neck
- Single most likely diagnosis:
- Cellulitis or Abscess: Given the patient's symptoms of sore throat, tender lymph nodes, erythema, and a recent history of trauma to the head, a bacterial infection such as cellulitis or an abscess is highly plausible. The negative strep test does not rule out other bacterial causes.
- Other Likely diagnoses:
- Lymphadenitis: Inflammation of the lymph nodes due to a bacterial or viral infection could explain the tender lymph nodes and swelling on the right side of the neck.
- Parotitis or Sialadenitis: Inflammation of the parotid gland could cause swelling and tenderness around the ear and neck, especially if the patient has a history of recent trauma or infection.
- Dental Abscess: A dental infection could cause referred pain to the ear and neck, as well as swelling and lymphadenopathy.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Lemierre's Syndrome: A rare but potentially life-threatening condition caused by a bacterial infection, typically Fusobacterium necrophorum, which can lead to sepsis and jugular vein thrombosis.
- Cancer (e.g., Lymphoma or Metastatic Disease): Although less likely, cancer should always be considered in the differential diagnosis of unexplained lymphadenopathy, especially in older adults.
- Tuberculosis or Atypical Mycobacterial Infection: These infections can cause lymphadenopathy and may not be immediately suspected, but are crucial to diagnose due to their potential for serious morbidity if left untreated.
- Rare diagnoses:
- Actinomycosis: A rare bacterial infection that can cause abscesses and lymphadenopathy, often associated with poor dental hygiene or recent dental procedures.
- Cat-Scratch Disease (Bartonellosis): Although more common in children, this disease can cause lymphadenopathy and should be considered if the patient has a history of recent cat scratches or exposure.
- Kawasaki Disease: An acute febrile illness that can cause lymphadenopathy, although it is more commonly seen in children.