Differential Diagnosis

The patient presents with a high white blood cell (WBC) count, high neutrophils, an enlarged posterior auricle lymph node, and difficulty swallowing. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Acute Bacterial Pharyngitis or Tonsillitis: This condition is likely given the symptoms of high WBC and neutrophil count, which indicate a bacterial infection. The enlarged lymph node near the ear (posterior auricle) could be reactive to the infection in the throat, and difficulty swallowing (dysphagia) is a common symptom of pharyngitis or tonsillitis.

• Other Likely Diagnoses

  • Mononucleosis (Infectious Mononucleosis): Caused by Epstein-Barr virus (EBV), it can present with lymphadenopathy (enlarged lymph nodes), sore throat, and elevated WBC count, although the increase is more commonly seen in lymphocytes rather than neutrophils.
  • Streptococcal Pharyngitis: Similar to acute bacterial pharyngitis, but specifically caused by Group A beta-hemolytic streptococci. It would also present with a high WBC count, neutrophilia, and lymphadenopathy.
  • Peritonsillar Abscess: A complication of tonsillitis, characterized by a collection of pus behind the tonsils, which could cause severe dysphagia and an elevated WBC count.

• Do Not Miss Diagnoses

  • Lymphoma: Although less likely, lymphoma could present with lymphadenopathy and systemic symptoms such as fever and weight loss. A high WBC count could be seen, especially if there's bone marrow involvement.
  • Tuberculosis (TB): TB can cause lymphadenopathy, and although it more commonly affects the lungs, it can present with systemic symptoms including fever and weight loss. A high WBC count might not be as pronounced, but it's crucial not to miss this diagnosis due to its public health implications and the need for specific treatment.
  • HIV Infection: Acute HIV infection can present with lymphadenopathy, sore throat, and a variety of other symptoms. While the WBC count might not always be elevated, the diagnosis is critical due to the long-term implications and the need for antiretroviral therapy.

• Rare Diagnoses

  • Castleman Disease: A rare disorder that involves an overgrowth of cells in the body's lymph nodes. It could present with lymphadenopathy and systemic symptoms, including fever and weight loss.
  • Kawasaki Disease: Although more common in children, Kawasaki disease can cause lymphadenopathy, fever, and other systemic symptoms. It's rare in adults but can be considered in the differential diagnosis, especially if other causes are ruled out.
  • Sarcoidosis: A condition that can cause inflammation in various parts of the body, including the lymph nodes. It might present with lymphadenopathy and systemic symptoms, although it's less likely to cause a significantly elevated neutrophil count.