allergic asthma
Introduction
Introduction to allergic asthma Allergic asthma is a relatively stubborn disease that can be associated with life if neglected. Most people with asthma have allergies or allergic rhinitis. Asthma patients with allergic rhinitis have symptoms of sneezing, runny nose, itchy nose, itchy eyes, and tearing. Because symptoms are similar to respiratory infections or inflammation, adults lack relevant knowledge and often ignore treatment at an early stage and are most likely to be misdiagnosed. basic knowledge The proportion of illness: 0.03% Susceptible people: no specific population Mode of infection: non-infectious Complications: chronic bronchitis obstructive emphysema chronic pulmonary heart disease mediastinal emphysema
Cause
Causes of allergic asthma
Causes
Inhalation: Inhalation is divided into specific and non-specific, the former such as dust mites, pollen, fungi, animal dander, etc.; non-specific inhalants such as sulfuric acid, sulfur dioxide, chloramine, etc., specific inhalation of occupational asthma Such as toluene diisocyanate, phthalic anhydride, ethylenediamine, penicillin, protease, amylase, silk, animal dander or excrement, etc. In addition, non-specific still exists formaldehyde, formic acid and the like.
Respiratory tract infections: The formation and onset of infection with asthma are associated with repeated respiratory infections. In asthma patients, there may be specific IgE of bacteria, viruses, mycoplasmas, etc. If the corresponding antigen is inhaled, it may trigger asthma. After the virus infection, Direct damage to the respiratory epithelium, resulting in increased respiratory responsiveness, some scholars believe that the interferon produced by viral infection, IL-1 increased the release of histamine from basophils, in the early childhood, respiratory viruses (especially respiratory syncytial virus) After infection, there are many symptoms of asthma symptoms. As a result of parasites such as aphids and hookworms, asthma is still seen in rural areas.
Dietary relationship: The phenomenon of asthma caused by food relationship is often seen in asthma patients, especially infants and young children are easy to be allergic to food, but gradually decrease with age, the most common food causing allergies is fish, shrimp and crab , eggs, milk, etc.
Climate change: When temperature, temperature, pressure and/or airborne ions change, asthma can be induced, so it is more common in cold seasons or in autumn and winter climate changes.
Asthma is related to drugs: some drugs can cause asthma attacks, such as propranolol, which causes asthma by blocking 2-adrenergic receptors. About 2.3% to 20% of asthma patients induce asthma by taking aspirin, called aspirin. Asthma, patients with nasal polyps and low tolerance to aspirin, it is called aspirin triad, its clinical features are: taking aspirin can induce severe asthma, symptoms appear more than 2 hours after medication, even late Until 2 to 4 hours, the patient may have cross-reaction with other antipyretic analgesics and non-steroidal anti-inflammatory drugs; children with asthma are mostly before the age of 2, but most of them are middle-aged patients, mostly from 30 to 40 years old. More women than men, the ratio of male to female is about 2:3; the attack has no obvious seasonality, the condition is heavier and stubborn, most of them are dependent on hormones; more than half have nasal polyps, often accompanied by perennial allergic rhinitis and Or) sinusitis, sometimes worsening asthma symptoms after nasal polyps resection; common inhalation allergen skin test is mostly negative; serum total IgE is normal; patients with less allergic diseases in the family, The pathogenesis of this disease has not been fully elucidated. Some people think that the patient's bronchial epoxidase may be affected by an infectious agent (probably a virus), which makes the epoxidase susceptible to aspirin inhibition, that is, intolerance to aspirin. Therefore, when patients use aspirin, it affects the metabolism of arachidonic acid, inhibits the synthesis of prostaglandins, and the imbalance of PGE2/PGF2, which increases the production of leukotrienes, leading to strong and long-lasting contraction of bronchial smooth muscle.
Prevention
Allergic asthma prevention
Prevention of asthma can be divided into 3 levels:
1. Level prevention refers to the purpose of preventing asthma by eliminating the asthmatic factors that are small in the surrounding environment.
2, level prevention refers to the early diagnosis and treatment of patients with major clinical symptoms of asthma to prevent the progression of the disease.
3, level top prevention refers to actively control asthma symptoms, prevent the disease from worsening, reduce complications, improve the quality of life of patients, and improve the patient's condition.
Complication
Allergic asthma complications Complications chronic bronchitis obstructive emphysema chronic pulmonary heart disease mediastinal emphysema
Long-term recurrent episodes may be complicated by chronic bronchitis, obstructive emphysema, chronic pulmonary heart disease and pulmonary interstitial fibrosis. In the attack period, pneumothorax and mediastinal emphysema may occur due to severe cough.
Symptom
Symptoms of allergic asthma Common symptoms Bronchial smooth muscle spasm, cough, asthma, sitting, breathing, tracheal obstruction, purpura, wheezing, chest tightness
Before the onset of allergic asthma, there are aura symptoms such as sneezing, runny nose, cough, chest tightness, etc. If not treated in time, asthma may occur due to aggravation of bronchial obstruction. In severe cases, it may be forced to take a seat or sit up and breathe, dry cough or slightly A large number of white foam sputum, and even cyanosis, etc., can generally be relieved by themselves or with self-medication or with anti-asthmatic drugs. Some patients may relapse after a few hours of remission, and even lead to persistent asthma.
In addition, clinically there are atypical manifestations of asthma, such as cough variant asthma, patients with no obvious cause of cough for more than 2 months, night and early morning attacks, exercise, cold air and other induced aggravation, airway reactivity determination exists Highly reactive, antibiotics or antitussive, antispasmodic treatment is ineffective, effective with bronchial spasmolytic agents or corticosteroids, but other diseases that cause coughing need to be ruled out.
Examine
Allergic asthma test
1. Blood routine: There is an increase in eosinophils at the time of onset; the total number of white blood cells and neutrophils increase when infected.
2. Sputum examination: mostly viscous sputum, eosinophilia, the formation of eosinophils can be found in the old sputum sputum; some loyalists can see the Cushman spirochete. May be small bronchi Management.
3. Pulmonary function test: All the indexes related to expiratory flow rate decreased during the attack, the main useful force first breath (FEVl), second rate (FRv1,%) and maximum expiratory flow rate (PEF), etc. Can be used for judgment of condition, treatment and assessment of pre-dust.
4. Blood gas analysis: mild hair author, Pao2, more normal, moderate to moderate and above, there are different degrees of decline, respiratory failure Pa02 less than 60mmHg, accompanied by hyperventilation, will lead to Paco 2 decreased and breathing Alkalosis; associated with airway obstruction, inadequate ventilation leads to an increase in Paco 2 and respiratory acidosis and/or metabolic acidosis.
5. X-ray examination: There may be no abnormality during the remission period. When the asthma attack occurs, the brightness of both lungs increases. The hyperinflation state, combined with pulmonary infection or secondary emphysema, pneumothorax and mediastinal emphysema have corresponding X-ray findings.
6 other checks
1 Allergen skin test, intradermal test with suspected allergens. It has certain value for determining allergies.
2 serum [BE and determination of eosinophil cationic protein content, etc. contribute to the diagnosis of asthma.
Diagnosis
Diagnosis of allergic asthma
diagnosis
According to the typical clinical symptoms and medical history, recurrent asthma, chest tightness, cough and two lungs can hear wheezing, there are some incentives for the attack, the symptoms can be relieved by bronchodilator or self-relieving, and other diseases can be ruled out. Pulmonary function test, FEV1 decreased, suggesting airflow obstruction; bronchiectasis test, after inhalation of bronchodilator, reduced FEV1 recovery is 15% positive, can be used as a diagnostic basis for asthma, bronchial provocation test to determine FEV1 or PEF lower than before drug absorption More than 20%, indicating an increase in airway reactivity.
In addition, it is often used in the intradermal test and prick test or in vitro determination of specific IgE in serum to detect and determine allergens, but there are certain limitations, bronchial provocation test, is of great significance for the diagnosis of occupational asthma.
Differential diagnosis
Allergic asthma should be noted with asthmatic bronchitis, cardiogenic asthma caused by left heart failure, dyspnea due to airway obstruction caused by airway tumors, pulmonary eosinophilic infiltration, and wheezing caused by bronchiolitis in children Identification.
