Pay attention to co-existing allergic diseases and provide comprehensive care for asthma patients

Author: Dai Ranran, deputy chief physician of Ruijin Hospital affiliated to Shanghai Jiaotong University School of Medicine

Reviewer: Tang Wei, Chief Physician, Ruijin Hospital, Shanghai Jiaotong University School of Medicine

Asthma is a relatively common respiratory disease. Patients usually experience wheezing, shortness of breath, coughing, chest tightness and other symptoms after inhaling allergens or certain irritating gases. Symptoms often occur and worsen at night and/or in the early morning. Most patients can relieve themselves or after treatment [1]. As for its etiology, allergies are a very important factor. According to the international authoritative medical journal The Lancet, the prevalence of asthma in people aged 20 and above in China is 4.20%, and there are approximately 45.7 million asthma patients nationwide; if children and atypical asthma patients are included, the number will exceed 60 million. This data far exceeds previous estimates, and more than 70% of these patients have not been clearly diagnosed in the past [2].

Figure 1 Copyright image, no permission to reprint

1. How to determine whether you have an allergic disease?

We can do relevant examinations, and as long as one of the following indicators is positive, the allergic disease can be diagnosed.

1. Allergen skin prick test (SPT): the diameter of the wheal or erythema caused by at least one allergen is larger than the negative control by 3 mm.

2. Elevated serum allergen-specific immunoglobulin E (IgE) levels (specific IgE > 0.35 IU/ml).

3. Elevated total IgE (＞60 IU/ml).

Some medical institutions do not have the conditions to conduct allergen or allergy status testing, and will choose to use the allergy screening questionnaire to understand and evaluate the patient's allergy status. The questionnaire mainly includes 7 questions. If the answer to any one question is affirmative, the patient is considered to be at risk of allergic disease and further blood tests are necessary to confirm the diagnosis.

The 7 questions are:

1. Are there any family members suffering from allergic diseases?

2. Do you currently or have you ever had frequent skin swelling or skin wheals?

3. Do you often sneeze or have an itchy nose?

4. Do you often have red, watery and itchy eyes?

5. Do you have a history of allergies to any food or medication?

6. Have you ever been diagnosed with an allergic disease by a doctor?

7. Have you ever used anti-allergy medications (e.g., antihistamines, topical corticosteroids)?

For asthma patients who visit the doctor for the first time, the doctor will ask the above questions and even scratch a mark on the patient's skin with his fingernail, asking him to continue to observe whether there are any changes in the skin at this point... Some people may wonder: "What is this for? I am here to see a doctor for asthma." Little do they know that asthma is the manifestation of allergic reactions in the lower respiratory tract. Although the respiratory department mainly treats asthma, in order to help patients recover better, it often also pays attention to other allergic diseases that asthma patients suffer from.

2. What are the main allergic diseases that asthma patients suffer from?

The allergic diseases that asthma patients suffer from mainly include the following.

1. Allergic rhinitis: This is the closest "partner" of asthma. Research data show that the proportion of asthma patients in my country with allergic rhinitis is 59.50% to 69.90% [3]. Allergic rhinitis can aggravate the severity of asthma. The typical symptoms of allergic rhinitis include nasal itching, frequent sneezing, runny nose, nasal congestion, and cough. These symptoms can occur suddenly, or they can resolve on their own or disappear quickly after treatment. Nasal symptoms often occur in the morning after getting up and before going to bed at night, and may worsen with the change of seasons.

2. Food allergy: A variety of food allergens can enter the body through ingestion or inhalation and induce allergic reactions. Children with food allergies have a nearly four-fold increased risk of developing asthma compared to those without food allergies, and often suffer from severe or persistent asthma. A national multicenter study on the prevalence of food allergies in urban asthmatic children in China showed that 8.77% of children were clinically diagnosed with food allergies, while the prevalence of food allergies in asthmatic children was 14.66%, and the prevalence of food allergies in non-asthmatic children was only 3.99%. The proportion of asthmatic patients with food allergies is also significantly higher than that of healthy people. About 4% to 24% of asthmatic patients have food allergies, of which nearly 50% have multiple food allergies [4]. Milk, eggs, wheat, peanuts, fruits, beef, pork and other foods may cause allergies. The manifestations of food allergies vary, among which rash is the most common, often occurring on the face, around the mouth, and also more common on the trunk, often accompanied by symptoms of itching and scaling, and may also cause abdominal pain, bloating, diarrhea, and increased bowel movements.

Figure 2 Copyright image, no permission to reprint

3. Atopic dermatitis: This is a chronic, recurrent, inflammatory skin disease, with recurrent chronic eczematoid rashes as the main clinical manifestation, accompanied by significant dryness and itching of the skin. Atopic dermatitis and allergic eczema belong to the same category of diseases. Most patients have atopic constitutions, often accompanied by allergic asthma. The treatment of atopic dermatitis is of great significance in alleviating the symptoms of allergic asthma patients, relieving their emotional disorders and improving their quality of life.

【References】

[1]Global Initiative for Asthma. Global strategy for asthma management and prevention, 2024[EB/OL]. [2024]. www.ginasthma.org.

[2]HUANG K, YANG T, XU J, et al. Prevalence, risk factors, and management of asthma in China: a national cross-sectional study[J]. Lancet, 2019, 394 (10196): 407-418.

[3]LIN J, SU N, LIU G, et al. The impact of concomitant allergicrhinitis on asthma control: a cross-sectional nationwide survey in China[J]. Asthma, 2014, 51(1): 34-43.

[4] Chinese Medical Association Allergy Branch Respiratory Allergy Group (Preparatory Committee), Chinese Medical Association Respiratory Disease Branch Asthma Group. Chinese Guidelines for the Diagnosis and Treatment of Allergic Asthma[J]. Chinese Journal of Internal Medicine, 2019, 58(9): 636-655.