Bronchial asthma is the most common chronic respiratory disease in the world. It is a hyperactivity to a variety of stimuli, leading to a variable degree of airway obstruction. Most frequently called an "asthma attack"' bronchial asthma causes period and frighting fits of coughing, wheezing, shortness of breath, and chest tightness.
Asthma is a chronic airway inflammation with cellular infiltration by T helper 2 cells, lymphocytes, oenophiles and mast cells with cytokine production. Airway obstruction occurs due to inflammatory cell infiltration, mucus hyper-secretion with mucus plug formation and smooth muscle contraction.
What are the causes of bronchial asthma?
• Atopy: Atopy is a predisposition toward developing certain allergic hypersensitivity reactions.
• Genetic factors: A hereditary component to asthma and atopy is well established.
• Hygiene: Asthma may be a by-product of modern cleanliness. Early life exposure to bacterial endotoxins switch off the allergic response. When this exposure is lost, the likelihood of developing allergic diseases such as asthma increases considerably.
• Other predisposing factors: Exercise, obesity, emotional stress and some drugs, such as aspirin, NSAIDs hypersensitivity or β-blockers.
Classically, symptoms are variable, intermittent, worse at night, associated with specific triggers, e.g. pollen, cat and dog dander, and non-specific triggers, e.g. cold air, perfumes, and bleaches, due to airway hypersensitivity.
• Shortness of breath.
• Chest tightness.
Each clinician will diagnose asthma differently; incorporating your symptoms, family history and diagnostic testing:
• Family history of asthma or other allergic diseases such as atopic dermatitis.
• Personal history of allergic diseases.
• Identify provoking factors, e.g. cold air, perfume, and environmental aeroallergens (grasses, pollen, hay), and any occupational exposures.
• Exclude other confusing conditions such as GERD (treating reflux may improve symptoms which have been wrongly attributed to asthma, particularly cough).
• Skin tests to define any allergens and possible triggers.
• Bronchodilator reversibility testing: An initial spirometry is performed to assess the patient's native respiratory status. The patient is asked to take a deep breath and then blow into the mouthpiece of the spirometer as hard as possible. This is a baseline measurement. A dose of bronchodilator medication is administered by means of inhaler or nebulizer (such as 400 mcg of salbutamol (also known as albuterol)). The patient waits about 15 minutes and then the spirometry is repeated. The result can confirm a positive diagnosis of asthma.
• If you have know allergens such as pets, pollen or certain foods- make sure to avoid them.
• Do not smoke, or be around second-hand smoke.
• Low magnesium intake is associated with increased asthma prevalence. Fish oils may be beneficial. Adjust your diet accordingly.
• Weight reduction in obese asthmatics leads to improved control.
• Desensitization using allergen-specific immunotherapy may be beneficial in a small subgroup of patients.
• Patients with asthma should receive pneumococcal vaccination and annual influenza. Inactive vaccines (Pneumovax) are associated with few side effects but use of the live attenuated influenza vaccine may be associated with asthma exacerbations in young children.
Pharmacological management is divided into those used for quick relief of symptoms and those for long term control. These drugs are for a quick relief of symptoms.
• Short-acting β-agonist (SABA), such as albuterol, are the most effective bronchodilators during exacerbations.
• Anticholinergic agent such as ipratropium bromide. They reverse vagally mediated bronchospasm but not allergen- or exercise-induced bronchospasm. They may decrease mucus gland hypersecretion. It is the inhaled drug of choice for patients with intolerance to beta-2-agonists or with bronchospasm due to beta-blocker medications.
• Systemic corticosteroids are effective primary treatment for patients with moderate to severe asthma exacerbations and for patients with exacerbations who do not respond promptly and completely to inhaled beta-2-agonist therapy. These medications speed the resolution of airflow obstruction and reduce the rate of relapse.
• Phosphodiesterase inhibitors such as theophylline are not recommended for therapy of asthma exacerbations.
• Beta-adrenergic agonists: They provide bronchodilation for up to 12 hours after a single dose. Salmeterol and formoterol are the two long- acting beta-2-agonists available for asthma in the United States. They are indicated for long-term prevention of asthma symptoms, nocturnal symptoms, and for prevention of exercise-induced bronchospasm.
• Anticholinergics: The long-acting anticholinergic tiotropium has been studied as add-on therapy.
• Phosphodiesterase inhibitors: Theophylline provides mild bronchodilation in asthmatic patients. Theophylline also has anti-inflammatory and immunomodulatory properties, enhances mucociliary clearance, and strengthens diaphragmatic contractility. Sustained-release theophylline preparations are effective in controlling nocturnal symptoms and as added therapy in patients with moderate or severe persistent asthma whose symptoms are inadequately controlled by inhaled corticosteroids.
• Leukotriene modifiers: Leukotrienes are potent biochemical mediators that contribute to airway obstruction and asthma symptoms by contracting airway smooth muscle, increasing vascular permeability and mucus secretion, and attracting and activating airway inflammatory cells. Zileuton, zafirlukast and montelukast are examples.
• Mediator inhibitors: Cromolyn sodium and nedocromil are long-term control medications that prevent asthma symptoms and improve airway function in patients with mild persistent or exercise-induced asthma. These agents modulate mast cell mediator release and eosinophil recruitment and inhibit asthmatic responses to allergen challenge and exercise-induced bronchospasm. They can be effective when taken before an exposure or exercise but do not relieve asthmatic symptoms once present.