Campbell had suggested that the cause of chronic bronchitis was due to toxic substances, and recommended pure air, simple food, and exercise to remove them from the body.A joint research programme was undertaken in Chicago and London from 1951 to 1953 in which the clinical features of one thousand cases of chronic bronchitis were detailed. The findings were published in the Lancet in 1953. It was stated that since its introduction by Badham, chronic bronchitis had become an increasingly popular diagnosis. The study had looked at various associations such as the weather, conditions at home, and at work, age of onset, childhood illnesses, smoking habits, and breathlessness. It was concluded that chronic bronchitis invariably led to emphysema, particularly when the bronchitis had persisted for a long time.In 1957 it was noted that at the time there were many investigations being carried out into chronic bronchitis and emphysema in general, and among industrial workers exposed to dust. Excerpts were published dating from 1864 in which Charles Parsons had noted the occurring consequence of the development of emphysema from bronchitis. This was seen to be not always applicable. His findings were in association with his studies on chronic bronchitis among pottery workers.A CIBA (now Novartis) meeting in 1959, and a meeting of the American Thoracic Society in 1962, defined chronic bronchitis as a component of COPD, in the terms that have not changed.
Eosinophilic bronchitis
Eosinophilic bronchitis is a chronic dry cough, defined by the presence of an increased number of a type of white blood cell known as eosinophils. It has a normal finding on X-ray and has no airflow limitation. Protracted bacterial bronchitis
Protracted bacterial bronchitis in children, is defined as a chronic productive cough with a positive bronchoalveolar lavage that resolves with antibiotics. Protracted bacterial bronchitis is usually caused by Streptococcus pneumoniae, non-typable Haemophilus influenzae, or Moraxella catarrhalis. Protracted bacterial bronchitis (lasting more than 4 weeks) in children may be helped by antibiotics. Plastic bronchitis
Plastic bronchitis is a rarely found condition in which thickened secretions plug the bronchi. The plugs are rubbery or plastic-feeling (thus the name). The light-colored plugs take the branching shape of the bronchi that they fill, and are known as bronchial casts. When these casts are coughed up, they are firmer in texture from typical phlegm or the short, softer mucus plugs seen in some people with asthma. However, some people with asthma have larger, firmer, and more complex plugs. These differ from the casts seen in people whose plastic bronchitis is associated with congenital heart disease or lymphatic vessel abnormalities mainly because eosinophils and Charcot–Leyden crystals are present in the asthma-associated casts but not in the others.Casts obstruct the airflow, and can result in the overinflation of the opposite lung. Plastic bronchitis usually occurs in children. Some cases may result from abnormalities in the lymphatic vessels. Advanced cases may show imaging similarities to bronchiectasis.