Some doctors believe that allergies are the common cause of cough in children and that allergen testing is needed to avoid exposure to allergenic foods.
Firstly, the conclusion of that question.
- 1. Food allergen testing has little reference significance for the diagnosis of the etiology of chronic cough, which is usually not recommended.
- 2. Food allergy seems very unlikely in cases of cough without other food allergy manifestations.
- 3. A positive allergen test does not mean that the food is allergic, so that there is no need to avoid eating it for this reason.
- 4. If there are no allergy-related symptoms, there is no need to take allergen test.
Next, we will explain the principle carefully.
1. Food allergy divided into IgE-mediated and non-IgE-mediated reactions,which is an abnormal reaction of the immune system after exposure to food antigens. The main difference between the two is the time of onset of action after exposure, with the former starting within minutes to 2 hours and the latter having a more chronic or subacute onset.
The manifestations of allergic reactions usually involve multiple systems such as the skin, digestive system, respiratory system, or cardiovascular system. Therefore, it is unlikely that an allergic reaction to food that causes only a chronic cough will occur.
In addition, most food allergies appear before the age of 2 years, and most foods to which children are allergic during childhood disappear over time. Similarly, foods that children are not allergic to before the age of 2 years are generally not allergic when they grow up.
2. There is no need to worry even if the allergy test is positive. There are 2 common tests for food allergies, one is a skin test and the other is a food-specific IgE test. False-positive results for the above tests are common, so clinicians also need to comprehend and interpret them in the context of the patient's clinical history.
3. Food allergies and chronic cough are not completely unrelated. Asthma is a common cause of chronic cough, and children with food allergies are at increased risk of developing asthma. If asthma is suspected to be related to food allergies, a more accurate food provocation test is needed to look for allergens. If it is just a chronic cough, go for the cause first rather than blindly testing for food allergens.
