Asthma is a chronic condition affecting the airways of the lungs. The hallmark symptoms of asthma are wheezing and difficulty breathing, but intermittent cough or chest tightness may be the only symptom. These respiratory symptoms usually come in episodes set off by various environmental or emotional “triggers.” Triggers include — but aren’t limited to — chemicals, pollution, pollen, animal dander, exercise, and smoke.
Acute bronchitis may occur as a primary infection of the respiratory tract but more commonly develops as a complication of an upper respiratory tract infection or as an exacerbation of acute infection in chronic bronchitis and emphysema.
Acute Bronchitis in previously healthy people:
It is usually preceded by an upper respiratory tract infection, and is caused by viral infections, particularly adenovirus, rhinovirus or influenza virus in adults and respiratory syncytial virus or parainfluenza virus in children and the elderly. More recently, secondary bacterial infection with Strep. pneumoniae and H. influenzae has been implicated. Atypical infections with Mycoplasma pneumonia, Chlamydia pneumonia and Chlamydia psittaci sometimes present as acute bronchitis in young adults. The organisms causing acute bronchitis are very similar to those causing more severe infections such as community-acquired pneumonia.
The common symptoms are mild general malaise, retrosternal soreness, and initially a dry tickly cough. Sputum is initially mucoid but may later become mucopurulent. Associated upper respiratory symptoms, including sore throat and running nose, are common.
Investigations are not usually required as the blood count may be normal and chest radiograph is normal. The C-reactive protein may be raised in the presence of bacterial infection. Sometimes, virus can be cultured from the nasopharyngeal secretions or a bacterial pathogen can be cultured from sputum.
The treatment is symptomatic and antibiotics may be prescribed depending on the duration of history, social factors, indications of bacterial infection, e.g. purulent sputum, and pre-existing medical conditions. Cough mixtures may be helpful at night, largely owing to their sedative properties.
Acute Exacerbation of chronic bronchitis:
Chronic bronchitis is characterised by production of excess mucus persistently for 3 months and successively for 2 years. These patients may suffer from acute exacerbations characterised by an increase in sputum purulence and worsening cough, lasting for 48 hours or more. Additionally, general malaise, mild fever, increased breathlessness, increased sputum volume or thickness, and increased difficulty in expectoration may be present. Such exacerbations may occur during winter months or with change of season due to superadded bacterial infections. Viruses may be responsible for 40% to 60% of acute exacerbations, particularly in winter months. However, Mycoplasma pneumoniae infection is associated uncommonly (1-8%) with these exacerbations. Variable wheezes and scattered coarse crepitations are heard on auscultation. Some peribronchial thickening or subsegmental infiltration may be observed on chest radiograph.
Antibiotics are usually required unless the exacerbation is very mild. Sputum culture is not necessary, unless the patient is very sick, or the presentation is unusual. Useful antibiotics are ampicillin, amoxycillin, co-trimoxazole and erythromycin given for 7 to 10 days. The associated problems of airflow obstruction, ventilatory failure and cor pulmonale are treated vigorously.
Acute Bronchitis and asthma:
Acute bronchitis may precipitate an attack of, or sometimes lead to the beginning of bronchial asthma. Acute viral infection (acute infective bronchitis) can lead to a state of airway hyperreactivity, may lead to persistence of cough and wheeze lasting for several weeks, and initiate the development of true asthma. Persistent cough and wheeze, particularly at night, together with a reduced peak-expiratory flow rate suggests the development of bronchial asthma.
Acute bacterial infections are an unusual cause of acute exacerbations of bronchial asthma, and therefore antibiotics are usually not required in the management of acute asthma.
Chronic Obstructive Pulmonary Disease (COPD):
Chronic obstructive lung (pulmonary) disease (COPD) denotes a generalised obstruction to the flow of air in the lung which is only partially reversible, or completely irreversible as in chronic persistent asthma and chronic bronchitis and emphysema.
Chronic bronchitis is characterised by cough with or without expectoration for at least 3 months of the year for 2 consecutive years.
Emphysema is defined as distension of the air spaces distal to the terminal bronchioles with destruction of alveolar septa.
Chronic bronchitis and emphysema frequently coexist. Chronic bronchitis, over a period of time, often gets complicated by emphysema. Most of the times it is difficult to separate one from the other.
I. Allergic rhinitis is the most common illness presenting as nasal itching, sneezing, discharge or nasal blocking.
A. Seasonal allergic rhinitis : Pollens of importance include tree pollens in spring and grass pollens during summer, weed, pollens and moulds.
B. Perennial rhinitis : House-dust mite (Dermatophagoides pteronyssinus, Dermato-phagoides farenae) are the commonest cause of perennial allergic symptoms. These are found in every house and accumulate in carpets, bedding, fabric and furniture. Domestic pets, e.g. cats, dogs and even cockroaches cause rhinitis.
Infection of the paranasal sinuses is prevented by the mucociliary apparatus which traps and removes microorganisms, pollutants, irritants and other foreign particles that escape the filtering apparatus of the nose. When this self-cleansing mechanism fails, bacterial infection occurs. The patency of the ostia is reduced by the swelling of the mucous membranes which leads to retention of secretions and low oxygen content within the sinuses, both of which favour increased bacterial growth and purulence. The factors predisposing to sinusitis are listed in Table.