Differential Diagnosis

The patient presents with symptoms of fever, running nose, nasal congestion, cough with thick phlegm, and headache. Based on the provided information, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis
  • Acute Viral Upper Respiratory Tract Infection (URTI): This is the most likely diagnosis given the symptoms of fever, running nose, nasal congestion, cough with thick phlegm, and headache. The presence of a productive cough with thick yellow phlegm and the absence of sore throat or sinus tenderness also support this diagnosis. The fact that no other household members are unwell and the patient's occupation as a painting inspector, quality controller, does not directly suggest an occupational exposure to a specific pathogen, further pointing towards a common viral infection.
• Other Likely Diagnoses
  • Acute Bronchitis: Although the chest examination shows clear breath sounds bilaterally, the productive cough with thick yellow phlegm could also suggest acute bronchitis, especially if the infection has moved down to the lower respiratory tract.
  • Influenza: Given the fever, cough, and headache, influenza should be considered, especially during flu season. However, the absence of myalgias and the nature of the cough (productive with thick phlegm) might slightly lower the likelihood compared to a common URTI.
• Do Not Miss Diagnoses
  • Pneumonia: Although the chest examination is clear, pneumonia can sometimes present with minimal or no findings on lung auscultation, especially in early stages or in partially treated cases. The presence of fever and productive cough necessitates considering pneumonia, as missing it could have serious consequences.
  • Sinusitis: Despite the absence of sinus tenderness on palpation, acute bacterial sinusitis could be considered, especially with symptoms of nasal congestion, headache, and fever. The diagnosis might require further evaluation, such as imaging or response to treatment.
  • COVID-19: Given the current pandemic situation, COVID-19 should always be considered in patients presenting with respiratory symptoms, even if they are mild. The presence of fever, cough, and headache could be consistent with COVID-19, and testing might be warranted based on epidemiological factors and clinical judgment.
• Rare Diagnoses
  • Tuberculosis (TB): Although less likely given the acute presentation and the absence of systemic symptoms like weight loss or night sweats, TB could present with cough and fever. It would be considered more likely in individuals with risk factors for TB exposure or in endemic areas.
  • Lemierre's Syndrome: This rare condition involves a bacterial infection of the tonsils leading to sepsis and thrombophlebitis of the internal jugular vein. The presence of mildly swollen tonsils and fever could prompt consideration of this diagnosis, although it is much less common and typically presents with more severe symptoms.