What Can Cause Asthma?
Many patients with asthma develop specific IgE antibodies to one or more environmental antigens (allergens). This form of the disease has received the name allergic bronchial asthma. It can be combined with diffuse neurodermatitis and hay fever.
Allergic asthma is also called exogenous, as opposed to idiosyncratic (endogenous) asthma, the pathogenesis of which play a role nor a predisposition to allergies or specific antigens in the environment. Allergic asthma usually develops in childhood and young age.
The most common allergens include pollen, fungi, house dust and epidermis of animals. Since dust particles are too large to reach the bronchi or effector cells (mast cells), asthma attacks, apparently provoked fragments of dust. The major allergens house dust Dermatophagoides pteronyssinus microclime, especially their feces. Common causes of asthma, especially among residents of crowded urban neighborhoods include the allergens of cockroaches. Among the allergens of cats is fundamental allergen contained in the secretion of the sebaceous glands of these animals. Many patients are allergic to the epidermis of dogs.
Food allergens are the cause of asthma is much rarer than air, but certain foods and food additives, such as metabisulfite (sometimes added to salads as preservatives) can provoke severe attacks. Reactions to foods are usually accompanied, or gastrointestinal disorders, or a rash. Often patients with bronchial asthma discover reflux esophagitis and its treatment can reduce the severity of asthma.
In the survey of adults is important detailed professional history. Substances that cause occupational asthma can be divided into low and high molecular weight. The first group includes, for example, toluylendiisocyanate used in the production of polyurethanes; bronchial asthma develops many months after the beginning of work with them. Compounds of platinum and various anhydrides cause bronchial asthma through stimulation of synthesis of specific IgE. To macromolecular compounds (proteins) are enzymes included in the composition of washing powders and detergents. An allergic reaction to them possible each of the fourth contacts of the worker.
Asthma cause many types of wood dust, especially dust giant arborvitae, better known as red cedar. Plumbers have asthma can develop as a result of inhalation of fumes released during soldering. Cotton and other fibrous types of organic dust can cause bronchospasm, causing the release of histamine. The disease known as byssinosis. Asthma can cause formaldehyde in high concentrations, but the same effect of small quantities of formaldehyde released from wood-fiber plates and the foams used in the home, unlikely.
Single heavy exposure to toxic fumes (e.g., ammonia, sodium hypochlorite, toluylendiisocyanate) can cause asthma in people without chronic diseases of the bronchi. This so-called syndrome of reactive bronchial dysfunction. The disease usually begins acutely in the first 24 h after contact with the irritating substance necessary medical care. After recovery can stay bronchial hyperreactivity, which is either gradually reduced over several months, or saved forever. Bronchial asthma is increased sensitivity of the Airways to a variety of nonspecific stimuli including cold air, perfumes, smoke and sulfur dioxide. An asthma attack can cause severe physical exertion and hyperventilation (spontaneous or induced laughter or crying). Attack due to physical stress can be prevented by prior inhalation cromolyn, nedocromil or beta-agonists. To nonspecific provoking factors include reflux esophagitis and chronic sinusitis.
Drugs cause approximately 10% of asthma attacks. More than half of them due to NSAIDs, especially aspirin. Intolerance to aspirin and other NSAID usually develops in 20-30 years, and apparently it's not genetic and acquired. Often bronchial asthma is preceded by a pronounced vasomotor rhinitis; characterized by nasal polyps and sinusitis. A few hours later after taking aspirin appear rhinitis and asthma. Possible nausea, vomiting, face oedema, angioedema and anaphylactic shock. This action of NSAIDs appears to be due to their ability to inhibit cyclooxygenase. Drugs that do not have this effect, such as salicylamide and sodium salicylate, considered safe. Paracetamol and dextropropoxyphene also relatively safe for the vast majority of patients with bronchial asthma. It is recommended that desensitization by daily administration of aspirin, but it is conducted by experienced allergist. The patient's condition can improve inhibitors of leukotriene receptors.
Bronchial asthma can provoke beta-blockers, including those which are part of eye drops, and even those who entered the breast milk. As in the lungs and beta1-adrenergic receptors in the heart and beta2-adrenergic receptors, it is necessary to select beta-blockers and their dose to achieve a cardioselective action. Heavy attack of a bronchial asthma can cause a antibiotics and iodinated contrast media. To reduce the severity of an attack pre-appoint H1-blockers and glucocorticoids. To provoke an attack of bronchial asthma can cocaine and a number of anesthetics.