Differential Diagnosis for a 33-year-old Female with Persistent URI Symptoms

Single Most Likely Diagnosis

• Acute Postviral Cough: This is the most likely diagnosis given the patient's history of upper respiratory infection (URI) symptoms followed by a persistent non-productive cough. The cough described as a "tickle in the back of the throat" is consistent with postviral cough, which often occurs after a viral upper respiratory infection.

Other Likely Diagnoses

• Allergic Rhinitis: The patient's symptoms of mild congestion and persistent cough could also be indicative of allergic rhinitis, especially if the symptoms are seasonal or triggered by specific allergens.
• Sinusitis: Although the patient does not have significant nasal congestion or facial pain, sinusitis could still be a consideration, especially if the cough is persistent and other symptoms like headache are present.
• Asthma: Cough can be a prominent symptom of asthma, and the description of the cough as a "tickle" could be consistent with asthma, especially if there are other symptoms like wheezing or shortness of breath.

Do Not Miss Diagnoses

• Pertussis (Whooping Cough): Although less common in adults, pertussis can cause a persistent cough and should be considered, especially if the cough is severe or if there has been exposure to someone with pertussis.
• Pneumonia: While the patient does not have other symptoms like significant shortness of breath or chest pain, pneumonia should always be considered in the differential diagnosis of a persistent cough, especially if there is a history of fever and chills.
• Tuberculosis (TB): TB is a less common cause of cough but is critical to consider due to its potential severity and the need for public health intervention. A history of exposure, travel, or immunocompromised state would increase the likelihood.

Rare Diagnoses

• Sarcoidosis: This is a rare condition that can cause cough among other symptoms. It would be considered if there were other systemic symptoms or findings suggestive of sarcoidosis.
• Foreign Body Aspiration: Although more common in children, foreign body aspiration can occur in adults and cause a persistent cough. This would be considered if there was a history of choking or if other symptoms like wheezing were present.