Differential Diagnosis for Nasal Obstruction, Purulent Nasal Discharge, and Maxillary Facial Pain
The patient's symptoms of nasal obstruction, purulent nasal discharge, and maxillary facial pain, particularly with a history of asthma and worsening symptoms despite over-the-counter decongestant medication, suggest an infectious process. The differential diagnosis can be categorized as follows:
- Single Most Likely Diagnosis
- Streptococcus pneumoniae: This bacterium is a common cause of community-acquired pneumonia and sinusitis, especially in adults. The patient's symptoms of nasal obstruction, purulent discharge, and facial pain are consistent with acute bacterial sinusitis, for which Streptococcus pneumoniae is a frequent culprit.
- Other Likely Diagnoses
- Haemophilus influenzae: Another common cause of respiratory infections, including sinusitis, Haemophilus influenzae can cause similar symptoms to Streptococcus pneumoniae and is often considered in the differential diagnosis for sinusitis.
- Moraxella catarrhalis: This bacterium is also a common cause of respiratory tract infections, including sinusitis, and should be considered, especially in patients who have not responded to initial treatments.
- Do Not Miss Diagnoses
- Invasive Fungal Sinusitis: Although less common, invasive fungal sinusitis can present with similar symptoms and is critical to diagnose early, especially in immunocompromised patients. It would be a deadly diagnosis if missed.
- Staphylococcus aureus: Including methicillin-resistant Staphylococcus aureus (MRSA), which can cause severe infections and should be considered, especially if there's no response to typical antibiotic treatments.
- Rare Diagnoses
- Parainfluenza: Typically causes respiratory infections in children, such as croup, but can cause sinusitis in adults, though it's less common.
- Anaerobic Bacteria: Can cause sinusitis, especially in cases of dental infections spreading to the sinuses or in immunocompromised patients, but are less common causes of community-acquired sinusitis.
Each of these organisms has a different implication for treatment, ranging from antibiotic selection to the need for antifungal therapy, highlighting the importance of accurate diagnosis.