Bronchitis

Bronchitis is rumored to be contagious although Bronchitis is the inflammation of the mucus membrane of the bronchial tree. They are of two types, namely acute and chronic bronchitis. The acute bronchitis is primarily due to viral infection which can readily develop to a secondary bacterial infection in a susceptible host. They are contagious. On the contrary, chronic bronchitis is caused by various other reasons like cigarette smoking or exposure to pollution and hence is non-contagious.

Acute bronchitis often follows the infections of the upper respiratory tract. When upper respiratory tract infections are adequately treated, acute bronchitis can be prevented. Apart from infection, inhalation of physical and chemical irritants, gases and other air contaminants can also cause acute bronchial irritation. This irritation causes dry, irritating cough with a scanty amount of mucopurulent sputum. When a culture of this sputum is collected and tested, it will show the growth of certain organisms like Streptococcus pneumoniae, Haemophilus influenzae or Mycoplasma pneumoniae. These organisms are highly contagious.

These organisms spread from one person (infected) to other through air particles while coughing, sneezing, talking, singing, using their fomite and even breathing. Proper disposal of sputum, good hygiene and appropriate medical treatment with antibiotics can prevent the spread of infection. Other symptoms may include sternal soreness from coughing, fever, headache, general malaise and noisy breathing (inspiratory stridor). They are treated with antihistamines, cough expectorants, steam inhalation, vapor therapy and increasing fluid intake.

Unlike acute bronchitis, chronic bronchitis interferes with effective breathing due to accumulation of secretion in the bronchioles and lower respiratory tract. The person is asymptomatic until they become susceptible to infections of the lower respiratory tract. They are easily prone to infections because of the accumulated secretions providing adequate nutrients for the organisms to grow. The major symptom is the presence of productive cough that lasts for 3 months a year for 2 consecutive years.

In chronic bronchitis, the smoke or pollutant irritates the airway which results in hypersecretion of mucus and reduces the function of cilia. Thus mucus coats the bronchioles, clogs and narrows the airway affecting normal air entry. The alveoli nearer to the bronchioles becomes fibrosed and the function of alveolar macrophages is altered, this makes the person more susceptible to infections. All these actions brings about an irreversible change in lungs resulting in emphysema and bronchiectasis. They together contribute to the major lung disease called chronic obstructive pulmonary disease (COPD).

As they are constrained to the lower respiratory tract, they are usually harmless by not being contagious. Cough is the main symptom and no signs of infection noticed in them. Cough is also exacerbated by cold weather, dampness or pulmonary irritants and not by infection. They are treated with oxygen therapy, bronchodilators, postural drainage, chest percussion, hydration and corticosteroids. This confirms they are not contagious.

To summarize, acute bronchitis which is primarily caused due to viral infection is contagious and chronic bronchitis which is caused by various other reasons like cigarette smoking or exposure to pollution are non-contagious.

Asthma

Asthma is a reversible obstructive airway disease that affects 17% of the American population. Although asthma can be fatal, more often it is just disruptive and affects day to day activities. Asthma can begin at any age, but in most cases it develops in childhood. Children usually develop allergic asthma which they outgrow by adolescence.

The common symptoms of asthma are cough, dyspnea and wheezing. These symptoms are manifested because of the narrowing of the airways. The symptoms and treatment of asthma depend upon the degree of airway narrowing. Asthma attacks frequently occur at night. The cause is not completely understood, but may be related to circardian variations, which influence the airway receptor thresholds. An asthmatic attack usually starts suddenly with coughing and a tight sensation in the chest. These symptoms are followed by slow, laborious, wheezy breathing. Generally expiration is always much more strenuous and prolonged than inspiration. This makes the asthmatics to sit upright and use every accessory muscle of respiration.

Obstructed air flow causes dyspnea. The cough at first is dry but soon it becomes forceful. Sputum, consisting of thin mucus containing small, round, gelatinous masses is coughed up with much difficulty. Later signs may include cyanosis (bluish discoloration) secondary to severe hypoxia, and symptoms of carbon dioxide retention, including sweating, tachycardia, and a widened pulse pressure. The symptoms of asthma may last from 30 minutes to several hours.

Other possible reactions that may accompany asthma include eczema, rashes, and temporary edema. The symptoms may occur periodically after exposure to a specific allergen, some medications, physical exertion, and emotional excitement.

Asthma symptoms can be reversed either spontaneously or by medical therapy. They can be effectively treated or controlled by medication therapy. There are five categories of medications that are used to treat asthma namely beta agonists, methylxanthines, anticholinergics, corticosteroids and mast cell inhibitors.

Beta Agonists:
Beta agonists are the initial medications used in the treatment of asthma because they dilate bronchial smooth muscles. They can also increase the ciliary movements and decrease the chemical mediators of anaphylaxis. The most commonly used beta adrenergic agents are epinephrine, albuterol, isoproterenol, metaproterenol and terbutaline. These medications are administered parenterally or by inhalation. Inhalation route is the best route of choice because it directly acts on the bronchioles and has only a few side effects.

Methylxanthines:
Methylxanthines, like aminophylline and theophylline are used in the treatment of asthme because of their bronchodilating effects. They relax the bronchial smooth muscles, increase movement of mucus in the airways and increase the contraction of diaphragm. Aminophylline is the IV form of theophylline and is administered intravenously. Theophylline is given orally.

Methylxanthines are not used in acute attacks because they are slow acting compared to beta agonists. There are several factors like tobacco smoking, heart failure, chronic liver disease, oral contraceptives, erythromycin and cimetidine which interfere with the metabolism of methylxanthines, particularly theophylline. Physician should be notified if any of the above mentioned condition exists before taking theophylline. Aminophylline should be administered very slowly, because giving them rapidly may cause tachycardia or cardiac dysrhythmias.

Anticholinergics:
Anticholinergic like atropine is not used in the routine treatment of asthma because of their systemic side effects such as dryness of the mouth, urinary hesitancy, blurred vision, palpitation and flushing. Atropine methylnitrate and ipratropium bromide have shown excellent bronchodilator effects with minimal side effects.They are administered by inhalation. Anticholinergics are particularly beneficial to asthmatics who are not candidates for beta agonists and methylxanthines because of underlying cardiac disease.

Corticosteroids: Corticosteroids are widely used in the treatment of asthma. These medicines can be administered intravenously (hydrocortisone), orally (prednisone), or by inhalation (dexamethasone, beclomethasone). The mechanism of action is not clear but they are thought to reduce inflammation and bronchoconstriction. Prolonged use of corticosteroids can result in serious side effects like peptic ulcers, osteoporosis, adrenal suppression, steroid myopathy and cataracts.

Inhaled corticosteroids are effective in the treatment of asthmatics with steroid dependent asthma. The advantage of this method of administration is the reduced side effects on other body systems. Throat irritation, coughing, dry mouth, hoarseness, and fungal infection of the mouth and pharynx may occur. Rinsing and gargling the mouth immediately after using inhaled corticosteroids will decrease the incidence of fungal infection. Any redness or presence of white patches in the mouth should be reported.

Mast cell inhibitors: Cromolyn sodium, a mast cell inhibitor is an integral part of the treatment of asthma. It is administered by inhalation. It prevents the release of chemical mediators of anaphylaxis, thereby resulting in bronchodilation and a decrease in airway inflammation. Cromolyn sodium is the most beneficial between attacks or while the asthma is in remission. It may result in the reduction of use of other medications and overall improvement in symptoms.

Status asthmaticus (severe and persistent asthma) is a medical emergency. The treatment is usually on an emergency room setting, and the person will be treated initially with beta agonists and corticosteroids. Oxygen therapy may be initiated for those who have dyspnea, cyanosis and hypoxemia.

These are the symptoms and treatment available for asthma. Identifying the early symptom and taking appropriate action will prevent emergencies.