Differential Diagnosis for Acute Interstitial Pneumonia
Single Most Likely Diagnosis
- Hamman-Rich Syndrome (Acute Interstitial Pneumonia): This is a rare, severe form of lung disease characterized by rapid onset of symptoms, including cough, fever, and shortness of breath, often leading to respiratory failure. It is considered the most likely diagnosis given the specific mention of "acute interstitial pneumonia."
Other Likely Diagnoses
- Influenza Pneumonia: Influenza can cause an interstitial pattern of pneumonia, especially in severe cases or during outbreaks of certain strains.
- Mycoplasma Pneumonia: This atypical pneumonia can present with interstitial infiltrates on chest imaging and is known for its community-acquired nature.
- Viral Pneumonias (e.g., COVID-19, RSV, Adenovirus): Various viral infections can lead to interstitial patterns of lung involvement, with COVID-19 being particularly notable for its potential to cause severe interstitial pneumonia.
- Connective Tissue Disease-Associated Interstitial Lung Disease (ILD): Conditions like rheumatoid arthritis, systemic lupus erythematosus, and scleroderma can have pulmonary manifestations, including acute interstitial pneumonia.
Do Not Miss Diagnoses
- Pneumocystis jirovecii Pneumonia (PCP): Especially in immunocompromised patients, PCP can present with a severe, life-threatening interstitial pneumonia that requires prompt treatment.
- Invasive Fungal Infections (e.g., Invasive Aspergillosis): In severely immunocompromised patients, these infections can mimic acute interstitial pneumonia and are critical to diagnose early due to their high mortality rate.
- Tuberculosis (TB): Although more commonly associated with cavitary lesions or upper lobe infiltrates, TB can present atypically, especially in immunocompromised patients, and must be considered to avoid missing a treatable condition.
Rare Diagnoses
- Eosinophilic Pneumonia: Characterized by the accumulation of eosinophils in the lungs, this condition can present acutely and may mimic other forms of interstitial pneumonia.
- Lymphangitic Carcinomatosis: Metastatic cancer to the lungs can cause an interstitial pattern of infiltration, although this is more commonly seen in the context of known malignancy.
- Acute Hypersensitivity Pneumonitis: An allergic reaction to inhaled antigens can cause an acute interstitial pneumonia-like syndrome, often in individuals with a history of exposure to specific substances (e.g., certain chemicals, bird droppings).
- Acute Radiation Pneumonitis: Following radiation therapy to the chest, patients can develop an interstitial pneumonia as a complication of their treatment.