Is it difficult to diagnose and treat cough variant asthma？ Professor Xie Jiaxing summarized four suggestions.

The original nine Wan Li sorted out the medical respiratory channels included in the collection #2022 world asthma day 5.

* For medical professionals only.

4 suggestions +2 expectations. What does Professor Xie Jiaxing say?

Asthma is one of the most common chronic respiratory diseases in the world. It is estimated that there is one asthma patient in every 20 people in the world, and there are about 20 million asthma patients in China. There is no cure for this disease. Fortunately, proper management and medication can control this disease and enable patients to live a normal and active life.

Therefore, it is very important for clinicians to make standardized diagnosis and treatment of patients to improve the control level of asthma and improve the quality of life of patients. May 3rd, 2022 is the 24th "world asthma day". The Medical Respiratory Channel is fortunate to invite Professor Xie Jiaxing from the Department of Respiratory Medicine of the First Affiliated Hospital of Guangzhou Medical University to teach us about the diagnosis and treatment of cough variant asthma (CVA). Let’s have a look!

Is it asthma or cough?

Please keep these two suggestions about diagnosis!

Professor Xie Jiaxing introduced that CVA is a special type of asthma. Although it has the same pathophysiological mechanism as classic asthma, its clinical manifestations are different. Cough is its only or main clinical manifestation, and there are no obvious symptoms such as wheezing and shortness of breath. Airway hyperresponsiveness is the most important feature of the disease.

The main clinical manifestation is irritating dry cough, which is usually severe. Cough at night and in the early morning is its important feature. Cold, cold air, dust and lampblack are easy to induce or aggravate cough.

As asthma, CVA has a place in chronic cough. Domestic multi-center survey results show that CVA accounts for about one-third of the causes of chronic cough and is one of the most common causes of chronic cough. Therefore, CVA needs to be differentiated from other chronic coughs, such as upper airway cough syndrome (UACS), eosinophilic bronchitis (EB), allergic cough (AC) and so on.

So, how do we diagnose CVA?

At present, the diagnosis of CVA should be based on the comprehensive analysis of symptom-driven, pulmonary function examination and the effectiveness of anti-asthma treatment, and the diagnosis can be made only if the following three conditions are met [1]:

(1) Chronic cough, often accompanied by obvious irritating cough at night.

(2) The bronchial provocation test is positive, or the average diurnal variation rate of PEF is more than 10%, or the bronchial relaxation test is positive.

(3) Anti-asthma treatment is effective.

Considering the current situation of equipment and personnel training in primary hospitals, Professor Xie Jiaxing offered two suggestions:

(1) pay attention to avoid misdiagnosis and missed diagnosis.

In clinical work, Professor Xie Jiaxing met many patients who were diagnosed with CVA in primary hospitals. Many cough patients were diagnosed with CVA only because of a positive bronchial provocation test, so they used many drugs to treat asthma.

But in fact, this condition alone is not enough to diagnose CVA, and we should fully consider it according to our diagnostic criteria. For example, the patient’s symptoms, does the cough last for a long time, often at night? For example, after asthma treatment, is the patient’s symptoms obviously relieved?

In addition, Professor Xie Jiaxing said: "We sometimes see it in clinic, because some grass-roots hospitals can’t carry out bronchial provocation test, and they do bronchodilation test. Perhaps the basic ventilation function of many CVA patients is normal, so it is difficult to make a positive result from the bronchodilation test. At this time, CVA may be missed because of negative results."

(2) Under limited conditions, consider the peak current meter to help check.

Considering that some primary medical institutions do not have the conditions for lung function examination, the peak current meter, as an instrument that can quickly and objectively reflect the peak expiratory flow rate (PEF), can monitor PEF and daily variation rate at any time, and record asthma diaries or draw charts to evaluate and monitor the severity of asthma, and can also find the regularity of asthma attack, which is equivalent to a sphygmomanometer commonly used in hypertension examination or a blood glucose meter commonly used in diabetes examination, and can play a certain role.

Grass-roots doctors can monitor for one week by using the peak current meter. If the PEF changes greatly and exceeds a certain value (for example, the weekly variation rate is more than 20%), it can also prove that patients may have airway hyperresponsiveness, which is helpful for the diagnosis of CVA.

Treatment of CVA, pay attention to patient compliance.

When talking about the treatment of CVA, Professor Xie Jiaxing said that the drugs and principles of CVA are basically the same as those of classic asthma, because they have the same pathophysiological mechanism, and early intervention will help to prevent CVA from developing into classic asthma.

Here are the treatment suggestions listed in the Guide to Diagnosis and Treatment of Cough (2021):

(1) It is recommended that inhaled corticosteroids be combined with bronchodilators, such as long acting beta-agonists (LABA) or inhaled corticosteroids alone (1B). Combined therapy can relieve cough symptoms more quickly and effectively than inhaled corticosteroids or bronchodilators alone, but more clinical research evidence is needed. The treatment time is more than 8 weeks, and some patients may need long-term treatment or intermittent treatment as needed. It is suggested to refer to the asthma treatment mode, evaluate the patient’s treatment response during the treatment and adjust the treatment plan (2D).

(2) If the patient has severe symptoms or airway inflammation, or has poor response to inhaled corticosteroid therapy, oral corticosteroid therapy (10~20mg/d for 3 ~ 5 days) or inhalation preparation of ultrafine particles can be used for a short time. Long-term oral corticosteroid therapy for CVA(2C) is not recommended.

(3) Leukotriene receptor antagonist is effective in treating CVA, which can relieve cough symptoms, improve the quality of life and slow down airway inflammation (2B). Leukotriene receptor antagonist therapy may be effective in a few patients who have failed to respond to inhaled glucocorticoid therapy. The course of treatment and its inhibitory effect on airway inflammation still need further study.

(4) Traditional Chinese medicine believes that CVA is related to wind evil invading the lung and lung qi failing to propagate, so the treatment should be dispersing wind and dispersing lung, relieving cough and relieving sore throat, and Suhuang Zhike Capsule has a certain effect (2B).

If inhaled corticosteroid treatment is ineffective for more than 4 weeks, it needs to be re-evaluated, and attention should be paid to whether there are diagnostic errors, false positive bronchial provocation test or other diseases, or some factors affecting the curative effect.

Therefore, inhaled glucocorticoids are the most commonly used drugs for CVA, but there is a problem of low patient compliance. Here, Professor Xie Jiaxing shared two points to improve patient compliance:

(1) reduce the fear of "hormones"

Many patients will have resistance when they hear the word "hormone". Clinicians can tell patients: "Inhaled glucocorticoids only work locally in our bronchi, and rarely enter the whole body. The side effects are very slight, so we usually don’t have to worry too much."

(2) emphasize not to stop taking drugs by yourself.

This is often the case in clinic. After several days of inhaled corticosteroid treatment, some CVA patients have completely recovered their self-feeling, or they will stop taking the drug on their own after taking the medicine for a period of time with the concept of "three drugs are toxic".

This requires clinicians to make it clear as soon as possible, so that patients can fully realize that this behavior of stopping taking drugs by themselves may lead to repeated illness, and the symptoms may only be relieved after taking drugs for a period of time. For example, "Although the symptoms are suppressed for a short time, chronic inflammation and hyperresponsiveness in the airway still exist, and stopping taking drugs by themselves may easily lead to recurrence or progress from CVA to more serious classic asthma. Therefore, stop taking drugs by yourself, and doctors will use instruments to check related indicators to determine whether you can reduce or stop taking drugs."

In addition, the determination of exhaled nitric oxide (FeNO) as a convenient method for airway inflammation has been popularized in most primary hospitals. If the result is significantly increased, it also suggests the possibility of CVA, and it can also be used to evaluate the patient’s treatment response and adjust the treatment plan.

Expectation and prospect

Professor Xie Jiaxing has been engaged in the diagnosis and treatment of respiratory diseases such as asthma for many years, and put forward two expectations for the diagnosis and treatment of asthma in the future:

(1) New drugs/therapies

At present, inhaled glucocorticoids, as commonly used drugs, need to be used by patients every day, which is prone to low patient compliance and inconvenient compared with other dosage forms such as oral administration. Then, it is expected that more convenient drugs or better alternative therapies will appear in the future, which will be more convenient to use and better control the airway inflammation and airway hyperresponsiveness of CVA, so that diseases can be better treated.

(2) Move towards precision medical care.

Precision medical care is the general direction of modern medical care. We have been carrying out all kinds of cutting-edge research to explore new treatment methods, new technologies and new hopes that are expected to cure various diseases. We also look forward to the development of CVA in this respect, such as clarifying the deep-seated causes of CVA, carrying out individualized radical treatment, completely avoiding CVA from progressing to classic asthma and blocking the disease process.

Expert introduction

Xie Jiaxing

The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Institute of Respiratory Health, Chief Physician of National Respiratory Medicine Center, and Academic Master Tutor.

Young Member of Respiratory Physician Branch of Chinese Medical Doctor Association

Vice Chairman of Youth Committee of Chronic Airway Diseases of China Medical Education Association

European respiratory society long-term scholarship winner

Advanced individuals in the prevention and control of epidemic situation in COVID-19 of the national health system.

Member of the Expert Group "Multidisciplinary Expert Consensus on Diagnostic and Therapeutic Criteria for Eosinophilic Granulomatous Polyvasculitis in China" (Chinese Journal of Tuberculosis and Respiratory Diseases, 2018,41(7):514-521).

Member of the Expert Group of "Multidisciplinary Expert Consensus on Differential Diagnosis of Pulmonary Eosinophilia-related Diseases in China" (Chinese Medical Journal, 2022,102(1):21-35).

Editor-in-chief of Differential Diagnosis of Pulmonary Eosinophilia-related Diseases (People’s Health Publishing House)

Editorial Board of Journal of Tuberculosis and Pulmonary Diseases

Main directions: eosinophilia, asthma and chronic cough.

Reference source:

[1] Asthma Group, Respiratory Branch, Chinese Medical Association. Guidelines for Diagnosis and Treatment of Cough (2021)[J]. Chinese Journal of Tuberculosis and Respiratory Diseases, 2022,45 (1): 13-46. DOI: 10.3760/CMA.J.CN112147-2021101-00755.

Asthma Group, Respiratory Branch, Chinese Medical Association. Guidelines for Prevention and Treatment of Bronchial Asthma (2020 Edition) [J]. Chinese Journal of Tuberculosis and Respiratory Diseases, 2020,43(12):1023-1048.

This article starts: medical respiratory channel

This article is organized as follows: Nine Wan Li.

Audit expert: Xie Jiaxing, First Affiliated Hospital of Guangzhou Medical University.

Editor in charge: Dai Dai Zhang Li

Copyright statement

Please contact authorization for the original reprint of this article.

– End –

Read the original text