The most common symptom of pneumonitis is shortness of breath, which may be accompanied by a dry cough. If pneumonitis is undetected or left untreated, you may gradually develop chronic pneumonitis, which can result in scarring (fibrosis) in the lungs. Signs and symptoms of chronic pneumonitis include: 
Shortness of breath
Cough
Fatigue
Loss of appetite
Unintentional weight loss
 When to call a doctor Call your doctor anytime you have difficulty breathing, no matter what might be the cause.