Differential Diagnosis for Cough, Chills, and Fatigue
Single Most Likely Diagnosis
- Viral Upper Respiratory Infection: This is the most likely diagnosis given the symptoms of cough, chills, and fatigue, which are common in viral upper respiratory infections. The lack of acute findings on the chest X-ray and unremarkable CBC and CMP also support this diagnosis, as viral infections often do not cause significant abnormalities in these tests.
Other Likely Diagnoses
- Acute Bronchitis: This condition is characterized by a cough and can be caused by viral or bacterial infections. The symptoms and negative chest X-ray could align with acute bronchitis, especially if the cough is productive.
- Influenza: Although the flu seasonality isn't mentioned, influenza can cause cough, chills, and fatigue. The absence of acute findings on the chest X-ray does not rule out influenza, as it primarily affects the upper respiratory tract.
- Pneumonia (Early or Mild): It's possible for pneumonia to present with minimal or no findings on a chest X-ray, especially in early or mild cases. The symptoms of cough, chills, and fatigue could be indicative of a mild pneumonia.
Do Not Miss Diagnoses
- Pulmonary Embolism: Although less likely given the presentation, pulmonary embolism can cause cough and fatigue, and it is crucial not to miss this diagnosis due to its high mortality rate. A negative chest X-ray does not rule out pulmonary embolism.
- Tuberculosis (TB): TB can present with chronic cough, chills, and fatigue. It's a critical diagnosis not to miss due to its public health implications and the need for specific treatment. A chest X-ray might be negative in early or extrapulmonary TB.
- Lymphoma or Other Malignancies: Though rare, malignancies can cause systemic symptoms like fatigue and can sometimes present with cough if there is pulmonary involvement. These diagnoses are critical not to miss due to their significant impact on prognosis and treatment.
Rare Diagnoses
- Sarcoidosis: This is a systemic disease that can affect the lungs and cause cough, among other symptoms. It's less likely but could be considered if other diagnoses are ruled out and there are other suggestive findings.
- Histoplasmosis or Other Fungal Infections: In endemic areas, fungal infections can cause respiratory symptoms. These would be rare diagnoses to consider, especially if the patient has been exposed to soil or birds, or has a compromised immune system.
- Connective Tissue Diseases (e.g., Lupus, Rheumatoid Arthritis): These diseases can have pulmonary manifestations, including cough, and systemic symptoms like fatigue. They would be rare considerations in the differential diagnosis but important to recognize due to their complexity and treatment requirements.