Treatment, Symptoms, Diagnosis, & Causes: Cough asthma (Cough Type Asthma), also known as cough variant asthma (Cough variant asthma, CVA), 1972 Nian Glaser The disease was first reported and named variant asthma, chronic cough refers to the primary or sole clinical manifestation of A special type of asthma. GINA (Global Asthma Prevention Initiative) clearly believes that cough variant asthma is a form of asthma, and its pathophysiological changes are the same as asthma, and it is also a sustained airway inflammation and airway hyperresponsiveness. Cough Variant Asthma Treatment, Symptoms, Diagnosis, & Causes. When bronchial asthma begins to develop, 5% to 6% is a persistent cough as the main symptom, mostly at night or in the early morning, often irritating cough, which is often misdiagnosed as bronchitis. The age of onset is higher than that of typical asthma. About 13% of patients are older than 50 years old, and middle-aged women are more common. In childhood, a cough may be the only symptom of asthma or even a precursor to bronchial asthma, and hospital patients have also increased significantly. Cough Variant Asthma Treatment, Symptoms, Diagnosis, & Causes
What We Will Learn:
1: Cough Variant Asthma Causes
2: Cough Variant Asthma Symptoms
3: Variant Cough Asthma Test
4: Cough Variant Asthma Diagnosis
5: Directional Diagnosis
6: Cough Variant Asthma Treatment
1: Cough Variant Asthma Causes:
The causes of cough asthma are complex, except for the subjective factors such as the patient’s own genetic quality, immune status, mental state, endocrine, and health status, allergens, viral infections, occupational factors, climate, drugs, exercise, and diet. Environmental factors are also important causes of asthma development.
2: Cough Variant Asthma Symptoms
Because cough variant asthma is the only symptom with a cough, the clinical features are lack of specificity and the rate of misdiagnosis is very high. Therefore, for a chronic recurrent cough, the possibility of the disease should be considered. Because 50% to 80% of children with cough variant asthma can develop typical asthma, 10% to 33% of adults with cough variant asthma can also develop into typical asthma. Many authors consider cough variant asthma as a precursor to asthma. Performance, so early diagnosis and early treatment of cough variant asthma are very important to prevent asthma. Mainly have the following clinical features:
1: Incidence population
The incidence of children is high, and more than 30% of children with a dry cough have been found to be associated with cough variant asthma. In adults, the age of onset of cough variant asthma is higher than that of typical asthma. About 13% of patients are older than 50 years old, and middle-aged women are more common.
A cough may be the only symptom of asthma, mainly long-term intractable dry cough, often induced by inhalation of irritating odor, cold air, exposure to allergens, exercise or upper respiratory tract infection, and some patients have no incentives. More intensified at night or in the early hours of the morning. Some patients have a certain seasonality, with more spring and autumn. Most patients have been treated with a cough and expectorant and antibiotics for a period of time, almost no effect, and the use of glucocorticoids, antiallergic drugs, β2 receptor agonists and theophylline can be alleviated.
3: History of allergies
The patient itself may have a clear history of allergic diseases such as allergic rhinitis and eczema. Some patients can be traced back to a family history of allergies.
3: Variant Cough Asthma Test:
1: Blood routine
Peripheral blood eosinophils increased at the onset.
2: Imaging examination
With no abnormalities, CT helps to rule out early interstitial lung disease and atypical bronchiectasis.
3: Pulmonary function and airway reactivity determination
It is an important indicator for diagnosing CVA and judging the efficacy. The degree of lung function decline in patients with CVA is not as good as that of typical asthma. In most patients, lung ventilation is completely normal, so it is difficult to make a judgment based on changes in lung function. In view of the presence of AHR in CVA, patients with suspected CVA can undergo bronchial provocation test or bronchial dilation test. For the first second forced expiratory volume (FEV1) >70%, the bronchial provocation test, FEV 1 <70%, bronchodilation test, and peak expiratory flow rate (PEF) were measured by the expiratory peak flow meter. It is a simple and portable dynamic monitoring method for lung function. It is easy to operate and cheap. The positive criterion is that the intra-day (or 2 weeks) mutation rate is ≥20%, and the positive judgment is airway hyperresponsiveness to diagnose CVA.
4: Assessment of airway inflammation
The pathological changes of CVA are airway inflammation, so the detection of airway inflammation indicators plays an important role in judging airway inflammation and assisted diagnosis.
I: Induced sputum (IS) is feasible cell classification and detection of soluble substances in sputum, reflecting the secretion of the airway. In the cells involved in CVA airway inflammation, the infiltration of eosinophils is most obvious, and the sputum is induced. Changes in acid granulocytes predict the development of CVA into typical asthma.
II: Bronchial lavage and alveolar lavage mainly reflect the peripheral airway inflammation below the sub-segment of the lung. The bronchial mucosa biopsy can directly obtain the pathological basis of airway inflammation.
III: Nitric oxide (FENO) in exhaled breath FENO is associated with airway inflammation and AHR in eosinophils. The level of FENO in patients with CVA and asthma is significantly higher than that of a chronic cough caused by other causes. Therefore, FENO has high sensitivity and specificity for the diagnosis of CVA and has important application value in the etiology diagnosis of a chronic cough.
IV: Exhaled air condensate (EBC) non-invasive detection technology, compared with induced sputum, bronchoalveolar lavage, etc., has real-time, simple, repeating characteristics, etc., can dynamically detect airway inflammation.
Although it can also have bronchospasm, it often occurs in the tiny bronchi of the distal end or transient paralysis, so the wheezing sound is not heard or rarely heard during the physical examination.
4: Cough Variant Asthma Diagnosis
The possibility of asthma should be considered when encountering a patient who is only complaining of a long-term cough (time greater than 3 weeks). Currently recognized diagnostic criteria in the USA:
1. A cough persists or recurrent >1 month, less sputum, increased after exercise, but no wheezing episode;
2. Symptoms occur mostly in the morning, at night or at bedtime;
3. Seasonal onset or exposure to irritating odors, such as suffocation, suffocation and other high-response symptoms;
4. Exclude other chronic respiratory diseases;
5. Antibiotics and symptomatic treatment> No improvement in symptoms in 2 weeks, but anti-allergy and
bronchodilators are effective;
6. With one or more of the following allergic diseases or medical history, the previous history of allergic rhinitis or allergic bronchitis, elevated peripheral blood eosinophils or serum immunoglobulin E (IgE) > 200 mg / L, 痰A large number of eosinophils, positive skin allergen test, family history of asthma
7. The bronchodilation test or the challenge test is positive, or the 24-hour peak expiratory flow rate (PEF) mutation rate is positive.
5: Variant Cough Asthma Directional Diagnosis
Because many diseases can cause a cough, the diagnosis of CVA must exclude the following common diseases: acute and chronic bronchitis, endobronchial tuberculosis, allergic cough, bronchiectasis, upper airway cough syndrome, gastroesophageal reflux, taking angiotensin Cough caused by invertase inhibitors, and the like. ‘Cough Variant Asthma Treatment, Symptoms, Diagnosis, & Causes’
6: Cough Variant Asthma Treatment
1. CVA Treatment & Principle
CVA is treated in the same way as typical bronchial asthma. The American ACCP (American College of Chest Physicians) guidelines believe that the vast majority of CVA patients are effective in inhaling bronchodilators and inhaled corticosteroids. Our country’s cough guidelines recommend that most CVA patients inhale low-dose glucocorticoids in combination with bronchodilators (β 2 receptor agonists or aminophylline, etc.), or a combination of the two. Similar to typical asthma, short-term oral low-dose glucocorticoid therapy may be equally effective in patients with CVA. The treatment time of CVA should be no less than 8 weeks. The study suggests that 30% to 54% of CVA patients can develop typical asthma without intervention, and early inhaled glucocorticoid therapy can effectively reduce the risk of CVA progression to typical asthma, so early standard treatment with inhaled hormones It is important to improve the prognosis of patients with CVA. Since many CVA patients have atopic properties, avoiding the exposure of the corresponding allergen is also important to prevent the progression of CVA.
2. Drug treatment
Mainly for the application of anti-inflammatory drugs and bronchodilators.
I: Bronchodilator For patients with intermittent cough symptoms, bronchodilators can be used as needed, with short-acting β 2 receptor agonists or theophylline. Long-acting β 2 receptor agonists or sustained-release theophylline may be added for symptoms of persistent coughing or inhalation of glucocorticoids that are not effective in controlling symptoms.
II: Inhaled corticosteroids Because CVA and typical asthma have eosinophilic airway inflammation and airway remodeling, inhaled corticosteroids (ICS) is the first-line treatment. Inhalation of hormone therapy should be started as soon as possible after diagnosis of CVA. Budesonide or fluticasone propionate is generally recommended in foreign guides, and higher doses may be required in some cases. If glucocorticoid inhalation treatment alone can not alleviate the symptoms, it should be treated with a bronchodilator. For most CVA patients, ICS treatment can quickly relieve the symptoms of a cough, and after a cough is relieved, you can consider gradually reducing the number of steps. However, a cough may recur after termination of ICS treatment. Some scholars recommend long-term ICS treatment in CVA patients to prevent progression to typical asthma and airway remodeling, but its effectiveness remains to be confirmed by prospective studies.
III: Leukotriene Receptor Antagonists The treatment of CVA recommended by the British Thoracic Society includes short-acting β 2 receptor agonists, inhaled hormones, and leukotriene receptor, antagonists. The US ACCP guidelines recommend that patients with CVA who have poor efficacy with inhaled steroids and bronchodilators may be treated with leukotriene receptor antagonists prior to oral steroid therapy after excluding factors such as poor adherence. Several studies have reported that anti-leukotriene receptor antagonist therapy is effective in relieving cough symptoms, reducing airway inflammation, and improving lung function in CVA patients, but the number of observations is small. Since leukotriene receptor antagonists have not been proven to prevent airway remodeling and progression to typical asthma, it is best to use ICS in the treatment of CVA with leukotriene receptor antagonists. Single-agent treatment with leukotriene receptor antagonists may be considered in patients with CVA who are intolerant or poorly adherent to ICS.
IV: Oral glucocorticoids when CVA patients using ICS treatment cannot effectively control the acute exacerbation of the disease, or because of inhaled hormone induced persistent cough can consider short-term oral hormonal therapy, the general course of treatment is 1 to 2 weeks after continued inhaled hormone therapy. “Cough Variant Asthma Treatment, Symptoms, Diagnosis, & Causes” Airway inflammation monitoring after routine treatment for CVA has shown that patients with persistent eosinophilic airway inflammation are more likely to benefit from escalating anti-inflammatory treatments.