The Aplication Of Atopy Patch Test In Finding The Allergens Of Children Allergic Diseases

The allergic dermatosis is caused by allergen through allergic response, it has a very high incidence rate of up to 50%. Failure in finding the right allergens of these diseases, such as atopic dermatitis and hives, not only brings great suffering to patients, but also inconvenience and difficulties to clinical diagnosis and therapy.At present, there are many methods to test the allergens, including in vivo and in vitro test. Up to date, the most popular way used clinically to test allergen is serum specific IgE antibody test (sIgE). However, it is useless in anaphylactic diseases caused by other three types of allergic response and allergic response mediated by IgG. Additionally, false negative results are prone to appear : 1) IgE will be largely exhausted if the patients are trapped in the fastigium of anaphylactic diseases or have experienced severe allergic response. 2) The allergen has bound to the cell receptor. 3) The patients have IgE Autoantibody in their bodies. Futhermore, some of patients with allergic symptoms are not resulted from allergic response. Therefore, a safe and reliable testing method is urgently needed and it is also easier to be accepted by the families of children with allergic diseases.The atopy patch test which can activate IgE-mediated rapid allergic response through allergen, mainly evaluates the relationship between allergen and eczema after eczema-like skin response in patients treated with patch test. The atopy patch test can not only test IgE-mediated allergic diseases but also allergic diseases independent of IgE mediation. At present, there is no report of application of atopy patch test in diagnosing allergen of allergic diseases in our country.The atopy patch test can find out the allergens in the allergic diseases, and it provides a secure and efficient therapeutic measure. So, it is an acceptant allergen detecting method.A total of 45 cases of atopic dermatitis and chronic urticaria were found based on clinical symptoms, all of these pediatric patients have themselves cured in the second clinical medical school of jilin university from December 2009 to December 2010 with an age ranges from 5 months to 14 years old. Firstly, these 45 patients received both atopy patch test and serum specific IgE test, and then positive rate was summarized based on level of response of atopy patch test. Based on types of diseases, these patients were divided into choronic urticaria and atopic dermatitis groups; on types of experiments, atopy patch test and serum specific immunoglobulin groups; on results of experiments, atopy patch test (+) serum specific immunoglobulin (-) and atopy patch test (-) serum specific immunoglobulin (+) groups. Finally, after statistical analysis through chi-square test, we got the following results and conclusions: 1) Among the 45 cases of patients, 36 are patch positive, positive rate is 80%. Elm is among the high antigen inhalation (69.44%), the high positive rate is 69.44% in the antigen ingestion, marine fish (66.67%), egg (61.11%). Positive rate of serum specific immunoglobulin group is 78%, and milk has a high rate of 29%. Altogether, these data demonstrate that both of inhalation and ingestion can cause allergy owing to complicated incentives of allergic diseases. 2) In this test, atopic dermatitis group has a higher patch positive rate than chronic urticaria, and the allergens are prawns, marine fishes, wheat, beef, elms and feathers. The allergens in the chronic urticaria which obtained a higher positive rate than that of atopic dermatitis are eggs, milk and cigarettes. 3) In this experiment, these two methods have a good consistency in testing prawns, beef and elms, P<0.05, no significant difference. The atopic patch test positive rate is higher in the testing of milk and wheat using these two methods, P>0.05, there is significant difference between them, indicating that atopic patch test has a higher sensibility than serum specific IgE (-) after milk and wheat stimulation. 4)The atopic patch test (+) specific IgE (-) has a higher positive rate than atopic patch test (-) specific IgE (+), showing that atopic patch test is more sensitive in diagnosing allergens of atopic dermatitis and chronic urticaria than serum specific IgE(-). 5) In the 45 cases of atopic patch test, one case is sensitive to one substance (1/45), three cases to two substance (3/45), four cases to three substance (4/45) and twenty-eight cases to four or more than 4 substance (28/45); Among the 45 patients, sIgE positive rate is 78% (35/45), two cases are sensitive to one substance (2/45), three cases to two substance (3/45), four cases to three substance (4/45) and twenty-nine cases to four or more than four substance (29/45), indicating patients with allergic skin diseases are sensitive to a variety of allergens under the state of high sensitivity. 6) Both of the two methods have consistent results. Atopic patch test is more sensitive in diagnosing chronic urticaria and atopic dermatitis than serum specific IgE. So integration of these two methods as well as medical history reference together can effectively find out the allergens of atopic diseases.The atopic patch test is more sensitive than serum specific immunoglobulin in diagnosing allergens. Moreover, they are not only consistent with each other, but also complement with each other. Therefore, combination of them or APT alone along with medical history reference is an effective approach to seek the allergens of atopic diseases.