Bronchitis is an inflammation in the lower airway of the respiratory system that can be allergic (caused by an allergic reaction) or nonallergic. Allergic bronchitis is also known as bronchial asthma or allergic asthma and shares the characteristics of asthmatic disease. Patients with allergic bronchitis need to avoid those allergens that trigger their symptoms.

Symptoms of nonallergic bronchitis can be similar to asthma and allergic bronchitis. There are two different types of non-allergic bronchitis:

• Acute bronchitis. An infection of the bronchial tubes that appears suddenly and usually stems from bacteria or a virus. This disorder comes on suddenly and may feature:
  
  
• • Cough that produces mucus; if yellow–green in color, a bacterial infection is more likely
    
    
  • Shortness of breath worsened by exertion or mild activity
    
    
  • Wheezing
    
    
  • Fatigue
    
    
  • Fever, usually low
    
    
  • Chest discomfort
    
    
  Acute bronchitis is usually treated with antibiotics and/or anti-inflammatory medications, such as corticosteroids. Symptoms usually disappear within a few weeks of the first dosage of medication.
  
  
• Chronic bronchitis. A long-term inflammation of the bronchial tubes, usually caused by years of smoking. Air pollution and industrial dusts and fumes can also cause this condition. It is often accompanied by persistent wheezing that is the result of infected mucus blocking the bronchial tubes, and inflamed bronchial walls.  Other symptoms include:
  
  
• • Cough that produces mucus; if yellow-green in color, a bacterial infection is more likely
    
    
  • Shortness of breath worsened by exertion or mild activity
    
    
  • Wheezing
    
    
  • Fatigue
    
    
  • Fever, usually low
    
    
  • Chest discomfort
    
    
  • Frequent respiratory infections (e.g., colds, flu-like illnesses)
    
    
  • Ankle, feet and leg swelling (edema)
    
    
  • Blue-tinged lips from low levels of oxygen (cyanosis)

Chronic bronchitis usually is accompanied by emphysema. When this is the case, the disease is known as chronic obstructive pulmonary disease (COPD). Antibiotics, bronchodilators and corticosteroids frequently are prescribed. Quitting smoking will likely reduce symptoms.

At present, no test is available that provides a definitive diagnosis of either acute or chronic bronchitis. Physicians will need to eliminate other possible conditions before diagnosing acute bronchitis using pulmonary function tests, medical history, reported symptoms, mucus analysis and other techniques.