Differential Diagnosis for Elevated WBC, Low Eosinophils and Lymphocytes, Cough, and Shortness of Breath
- Single Most Likely Diagnosis
- Pneumonia: This is the most likely diagnosis given the symptoms of cough, shortness of breath, and elevated WBC count, which indicates an infection. The low eosinophils and lymphocytes could be due to a bacterial infection, which often causes a neutrophilic predominance.
- Other Likely Diagnoses
- Chronic Obstructive Pulmonary Disease (COPD) Exacerbation: COPD exacerbations can present with increased WBC count, cough, and shortness of breath. The low eosinophils and lymphocytes could be seen in COPD, especially if there is a bacterial component to the exacerbation.
- Acute Bronchitis: Similar to COPD, acute bronchitis can cause an elevated WBC count, cough, and shortness of breath, with low eosinophils and lymphocytes if the cause is bacterial.
- Influenza: Influenza can cause an elevated WBC count, cough, and shortness of breath, especially in severe cases. The low eosinophils and lymphocytes could be seen in influenza, particularly if there is a secondary bacterial infection.
- Do Not Miss Diagnoses
- Pulmonary Embolism: Although less likely, pulmonary embolism can cause shortness of breath and cough, and an elevated WBC count can be seen in response to the stress of the embolism. It is crucial to consider this diagnosis due to its high mortality rate if missed.
- Sepsis: Sepsis can cause an elevated WBC count, and if the source of sepsis is pulmonary (e.g., pneumonia), it could also cause cough and shortness of breath. Sepsis is a life-threatening condition that requires prompt recognition and treatment.
- Rare Diagnoses
- Lymphangitic Carcinomatosis: This is a rare condition where cancer spreads to the lymphatics in the lungs, causing shortness of breath and cough. The elevated WBC count could be seen in response to the tumor or secondary infection.
- Eosinophilic Pneumonia (with atypical presentation): Although eosinophilic pneumonia typically presents with elevated eosinophils, some cases can have a low eosinophil count, especially if treated with corticosteroids. This diagnosis should be considered if other causes are ruled out and there is a high clinical suspicion.