Bronchial asthma (asthma for short) is a chronic inflammatory disease of the airways in which genes, environmental factors, respiratory cells, and released cytokines are among the components involved in the development of this process. Our country has the highest mortality rate of asthma patients in the world. There are about 30 million patients in the country, with a prevalence of 0.7-1.5% in adults and 1.97% in children. These data show from the side that there is a serious deficiency in the prevention and treatment of asthma in China.
Asthma is a chronic inflammatory airway disease that cannot be cured, but only controlled, and has the potential for recurrent attacks. If left untreated, asthma in children will affect their lung function for life. Asthma is treated primarily with glucocorticoids to achieve and maintain clinical symptom control, failing to target the cause.
Occasional coughs and asthma in children can be life-threatening in a single attack if parents do not pay attention to them in general. In this regard, experts remind that asthma is a chronic inflammatory disease of the airways, with the possibility of recurrent attacks, and the treatment of asthma in children is a “constant battle”, so it is important to educate and train parents about asthma.
Specific immunotherapy is considered to be the only treatment for the cause of asthma and is an important direction of research today. Desensitization therapy involves making a leachate of a certain concentration of a major antigenic substance that cannot be avoided and that has been confirmed or suspected by skin tests or other methods, and injecting it in gradually increasing doses and concentrations to induce the body to produce the corresponding antibodies by repeatedly injecting the patient with the specific antigen.
Specific allergen desensitization therapy is currently the only treatment method for the cause of bronchial asthma, which has a history of more than 90 years, and its specific treatment mechanism has made great progress, but is still not fully understood. The main routes of desensitization therapy are subcutaneous injection, sublingual administration, nebulized inhalation, etc.
Is there value in desensitization therapy for pediatric asthma?
Desensitization therapy, also known as specific immunotherapy, is theoretically a radical therapy, but it is difficult to find all the allergens and eradicate the disease because it is difficult to find the right allergens. Therefore, the effective rate is around 80%, while the cure rate is <5%, so the therapy is limited. The current evaluation of desensitization therapy is more derogatory than positive, and the controversies focus on.
(1) desensitization therapy cannot improve the airway inflammatory response and needs to be replaced by anti-inflammatory drugs, and it is inconclusive whether desensitization therapy can reduce airway hyperresponsiveness.
(2) The efficacy of desensitization therapy is not superior to that of long-term application of bronchodilators or sodium cromoglycate, and desensitization therapy can induce asthma and even cause anaphylaxis.
(3) The allergens (allergens) of desensitization therapy are artificially “purified”, and there are qualitative differences with the natural allergens, and the way of entering the human body is different, the former through subcutaneous injection, the latter through the inhalation route, some natural allergens such as cold air and paint, smoke smell can not be purified, so there are great limitations. Currently, the number of foreigners applying desensitization therapy is decreasing.
(4) Desensitization therapy for bronchial asthma has a certain scope of application. Not all allergic asthma requires or has the possibility of specific desensitization therapy, but only for chronic asthmatics with a history of allergen-induced symptoms and specific IgE antibodies confirmed by skin tests and/or in vitro assays. Before application, firstly, the allergens should be selected for immunotherapy in allergic asthma patients, noting that they should be symptom-inducing allergens and not only those with positive skin tests; secondly, they are also indispensable allergens in daily life, such as: pollen, dust mites and certain fungi. However, tree pollen is not advocated among pollen, such as: pollen of willow, cypress, elm, etc., because their drifting season is very short and immunotherapy has no practical value.
(5) Pediatric allergens are diverse, and desensitization therapy can only target one type (dust mites mainly) at present, and even if desensitization is solved, other allergens cannot be solved.
(6) Pediatric allergens are variable and may be allergic to different substances at different stages of a child’s life.
From the above point of view, I do not recommend desensitization therapy for children.
What should I be aware of when treating pediatric asthma with desensitization therapy?
Desensitization therapy is not effective for any type of asthma. Therefore, it is important to pay attention to the indications during application. The currently accepted indications are.
(1) Patients with asthma mediated by immunoglobulin IgE, with positive skin tests and elevated serum specific r.
(2) A history of asthma induced by exposure to specific allergens (allergens). For late (late-onset) asthma reactions in which the allergen is difficult to identify, a provocation test with the suspected allergen is required if necessary.
(3) It is suitable for age 5 years or older and is performed during the remission phase of asthma, where the exertional expiratory volume in 1 second (FEV1) needs to reach 70% of the expected value.
The following points should also be considered in the specific application.
(1) Desensitization therapy should be administered by an experienced physician. Standardized and high quality leachate of the allergen in question should be used for the elicitation test in order to avoid allergic reactions. If an allergic reaction occurs, it can be treated promptly.
(2) Desensitization therapy is not effective for asthma caused by multiple allergens or non-allergens.
(3) Pay attention to safety, especially for those with severe asthma ventilation disorders, where side effects occur more severely.
(4) Observation should be made for more than 30 minutes after injection at the place of consultation, so that allergic reactions, especially anaphylactic shock, can be treated promptly in case of occurrence.