Cough asthma

　　The occurrence of cough asthma has both subjective and environmental factors. The specific etiology and pathogenesis are described as follows.

　　First, Etiology

　　The etiology of cough asthma is complicated. In addition to the patient's own genetic constitution, immune status, mental and psychological state, endocrine and health status, etc., allergens, viral infections, occupational factors, climate, drugs, exercise, and diet are also important causes of asthma development.

　　Second, Pathogenesis

　　Currently, there are two explanations for the pathogenesis of cough asthma:

　　1, The etiology of cough asthma is complex. The quality and quantity of allergenic and/or non-allergenic stimuli are not consistent, and individual differences exist due to genetic constitution, leading to different responses of the body to stimuli. The main pathological change of asthma is chronic non-specific inflammation of the airways, which further leads to bronchospasm, edema and hypertrophy of the airway mucosa, increased mucus secretion, dysfunction of mucosal cilia, and bronchial mucus栓塞.

　　2, Cough is an innate protective mechanism for clearing foreign matter or mucus, secretions from the airways.

　　Positive bronchial provocation test, when a positive reaction occurs, it can cause cough similar to that during an attack, indicating the presence of high airway reactivity; reversible airway obstruction test is positive. Cough asthma can be complicated by hypoxemia, pneumothorax, mediastinal emphysema, and in severe cases, it can develop into acute pulmonary edema.

　　Cough asthma often occurs at night or in the early morning, usually with a irritating cough, and its specific clinical manifestations are described as follows.

　　1. In adults with cough asthma, the onset age is higher than that of typical asthma, with about 13% of patients being over 50 years old, and middle-aged women are more common. In the childhood, cough may be the only symptom of asthma, or even a precursor to the development of bronchial asthma.

　　2. There is often a clear family history of allergies or a history of allergic diseases in other parts, such as allergic rhinitis, eczema, etc.

　　3. Attacks are often seasonal, with spring and autumn being more common.

　　4. The main clinical manifestations are long-term persistent dry cough, often induced by exercise, inhalation of cold air, or upper respiratory tract infection, and exacerbated at night or in the early morning. There is no wheezing on physical examination, the lung function damage is between normal people and typical asthma, and the skin allergen test may be positive.

　　5. The bronchial provocation test is positive. When a positive reaction occurs, there may be刺激性咳嗽 like the onset of the disease, indicating the presence of airway hyperreactivity; the reversibility test of airway obstruction is positive.

　　6. General cough and expectorant drugs and antibiotics are ineffective, while antihistamines, β2-agonists, theophylline, or adrenal cortical hormones can relieve symptoms.

　　The prevention of cough asthma includes avoiding allergens, avoiding triggers, and enhancing the body's immune function, and specific preventive measures are described as follows.

　　1. Actively search for sensitizing sources

　　Observe carefully the factors present before each cough attack, identify the sensitizing factors, avoid them, and prevent re-exposure. Common allergens such as dust mites, pet fur, cockroaches, pollen, and装修 pollution should be avoided.

　　2. Avoid triggers

　　The triggers of cough variant asthma attacks may include three possibilities: first, changes in climate, with cold air stimulation as the main trigger. In winter, when going out in the morning, it is necessary to wear warm clothes and wear a mask; second, coughing after exercise may worsen, so it is best to avoid strenuous exercise or to take antispasmodic drugs before exercise; third, emotional excitement or crying can also trigger cough attacks, so it is best to maintain emotional stability.

　　3. Enhance the body's immune function

　　Pay attention to prevent respiratory infections such as colds, because viral infections can also trigger cough variant asthma. The essence of cough variant asthma is still asthma, and asthma is an allergic disease, that is, allergic reactions caused by abnormal immune function. Therefore, attention should be paid to improve and enhance the body's immune function.

　　4. Diet

　　Allergens vary from person to person, and not all patients are unable to eat seafood, fish and shrimp, mutton, milk, and other easily allergic foods. Only those who are allergic after eating should avoid them.

　　The examination for cough asthma includes bronchial provocation test, chest X-ray examination, lung function test, and other specific examination methods are described as follows.

　　1. The bronchial provocation test is positive.

　　2. Chest X-ray examination is normal.

　　3. Most pulmonary function tests are normal, while a few patients may have mild obstructive ventilatory dysfunction, FEV1/FVC (one-second forced expiratory volume/forced vital capacity)

　　Cough asthma patients should eat foods with the effects of relieving asthma, coughing, and expectoration; avoid eating dry, fried, and foods with high content of allergens. The specific dietary precautions are described as follows.

　　1. Do not eat spicy foods: Spicy foods such as chili, pepper, garlic, scallion, chive, etc., can stimulate the respiratory tract and worsen symptoms; the seasoning of dishes should not be too salty or too sweet, and the temperature should be moderate.

　　2. Avoid seafood and greasy foods: Because 'fish generates fire, meat generates phlegm', children with chronic bronchitis should eat less yellow croaker, hairtail fish, shrimp, crab, and fatty meat, etc., to avoid helping fire and producing phlegm.

　　3. If a child's cough does not heal for a long time, it will consume the vital energy, weaken the lung and spleen. Therefore, it is advisable to choose foods with健脾,益肺,补肾,理气,化痰 functions in daily life, such as pork, beef, mutton lungs, loquat, orange, pear, lily, jujube, lotus seed, almond, walnut, and honey, which can help enhance the physique and improve symptoms.

　　4. Light diet: Fresh vegetables such as cabbage, spinach, rapeseed, radish, carrot, tomato, cucumber, winter melon, etc., can not only supplement a variety of vitamins and inorganic salts but also have functions such as clearing phlegm, reducing fire, and promoting defecation; soybeans and soy products contain high-quality protein needed by the human body, which can supplement the nutritional loss caused by chronic tracheitis to the body and do not have the disadvantage of producing phlegm and fire.

　　The essence of cough asthma is similar to typical asthma, which is a chronic non-specific inflammation of the airway caused by allergens or other triggering factors, as well as the airway hyperreactivity and stubborn cough formed on this basis. Therefore, the treatment principles are similar to those of typical asthma, mainly using bronchodilators, oral theophylline drugs and (or) β2-agonists. Some antiallergic drugs and drugs that stabilize mast cells, such as nedocromil, cromolyn, and ketotifen, can also achieve good effects. If these drugs do not show efficacy, consider using adrenal corticosteroids, adding beclomethasone dipropionate (disoproportionate beclomethasone) aerosol or oral prednisone, and another option is to try anticholinergic drugs for inhalation.