Differential Diagnosis for Pneumonitis
When considering pneumonitis as a diagnosis, it's essential to evaluate other potential causes of similar symptoms. Here's a categorized differential diagnosis:
- Single most likely diagnosis
- Influenza pneumonia: This is a common cause of pneumonitis, especially during flu season. The symptoms of influenza pneumonia, such as cough, fever, and shortness of breath, can be similar to those of pneumonitis.
- Other Likely diagnoses
- Community-acquired pneumonia (CAP): CAP is a common condition that can present with symptoms similar to pneumonitis, such as cough, fever, and chest pain.
- Acute bronchitis: Although typically less severe than pneumonitis, acute bronchitis can cause similar symptoms, including cough and shortness of breath.
- Chronic obstructive pulmonary disease (COPD) exacerbation: A COPD exacerbation can cause increased symptoms of cough, shortness of breath, and chest tightness, which may be similar to those of pneumonitis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Pulmonary embolism: Although less common, pulmonary embolism can present with sudden onset of shortness of breath and chest pain, similar to pneumonitis. Missing this diagnosis can be fatal.
- Tuberculosis: TB can cause chronic pneumonitis-like symptoms, and missing this diagnosis can lead to severe consequences, including transmission to others and development of drug-resistant strains.
- Pneumocystis jirovecii pneumonia (PCP): PCP is a life-threatening condition that can cause pneumonitis-like symptoms in immunocompromised individuals, such as those with HIV/AIDS.
- Rare diagnoses
- Eosinophilic pneumonia: A rare condition characterized by an accumulation of eosinophils in the lungs, which can cause pneumonitis-like symptoms.
- Hypersensitivity pneumonitis: A rare condition caused by an allergic reaction to inhaled substances, such as mold or dust, which can cause pneumonitis-like symptoms.
- Lymphangitic carcinomatosis: A rare condition characterized by the spread of cancer to the lymphatic vessels in the lungs, which can cause pneumonitis-like symptoms.