Differential Diagnosis

• Single most likely diagnosis:
  • Pharyngitis (likely viral or bacterial, given the symptoms of sore throat and cough, but the incomplete course of antibiotics complicates the picture)
    • Justification: The patient presents with classic symptoms of pharyngitis, including a sore throat and cough. Although the throat is still swollen and the patient hasn't completed the antibiotic course, the initial prescription of amoxicillin suggests a bacterial cause was considered. The improvement in symptoms before stopping the medication could indicate a viral etiology or a partial response to the antibiotic.
• Other Likely diagnoses:
  • Incomplete treatment of bacterial pharyngitis (e.g., streptococcal pharyngitis)
    • Justification: The patient was prescribed amoxicillin but did not complete the course, which could lead to incomplete treatment of a bacterial infection.
  • Viral upper respiratory infection
    • Justification: The symptoms of sore throat, cough, and decreased appetite are common in viral upper respiratory infections, and the fact that symptoms improved slightly before stopping the antibiotic could suggest a viral etiology.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Rheumatic fever
    • Justification: Given the family history of a cousin who died from heart complications related to rheumatic fever, it's crucial to consider this diagnosis, especially if the patient's symptoms are due to a streptococcal infection.
  • Peritonsillar abscess
    • Justification: Although less common, a peritonsillar abscess is a serious complication of tonsillitis that requires prompt diagnosis and treatment to avoid severe consequences.
• Rare diagnoses:
  • Lemierre's syndrome
    • Justification: This is a rare but serious condition involving a bacterial infection of the throat that spreads to the jugular vein, leading to thrombophlebitis. It's essential to consider in cases of severe or persistent pharyngitis.
  • Infectious mononucleosis
    • Justification: Caused by Epstein-Barr virus, this condition can present with sore throat, fever, and fatigue, among other symptoms. It's less common in young children but should be considered in the differential diagnosis of prolonged or atypical pharyngitis.