Ⅰ. Skin prick test
Principle:
The skin prick test is a common allergen detection method. A small amount of soybean extract is dropped on the skin, and then a specially made needle is used to gently prick the surface of the skin to allow the extract to enter the skin. If a person is allergic to soybeans, the immune system will recognize the allergen protein in soybeans. Within 15 - 20 minutes, the skin prick site will show reactions such as redness, swelling, and itching similar to mosquito bites.
Operation process:
It is generally carried out in the allergy department or dermatology department of a medical institution. Medical staff will first clean the skin of the test site (usually the inner side of the forearm), then drop different allergen extracts (including soybean extract) in turn, and then operate with a prick needle. During the test, the patient needs to keep the skin clean and avoid scratching the prick site to avoid affecting the result judgment.
Accuracy and limitations:
The skin prick test is a relatively rapid, simple, and economical detection method and has high sensitivity for detecting IgE-mediated allergic reactions. However, it also has certain limitations. False positive results may occur. For example, people with overly sensitive skin may have a mild reaction even if they are not truly allergic. At the same time, it can only detect immediate allergic reactions and may not be able to detect some delayed allergic reactions.
Ⅱ. Blood specific IgE detection
Principle:
When the human body is allergic to soybeans, the immune system will produce specific immunoglobulin E (IgE) against soybean allergens. By collecting a blood sample, the level of soybean-specific IgE in the blood is detected. If the detected specific IgE level is higher than the normal reference value, it suggests that there may be an allergy to soybeans.
Operation process:
In medical institutions, medical staff will draw a certain amount of blood from the patient's vein (usually a few milliliters) and then send the blood sample to the laboratory for detection. The laboratory uses specific detection methods such as enzyme-linked immunosorbent assay (ELISA) or fluorescence enzyme immunoassay to quantitatively detect the concentration of soybean-specific IgE.
Accuracy and limitations:
Blood specific IgE detection is a relatively accurate detection method, unaffected by skin conditions and drugs, and can detect some allergic conditions that may be missed by skin prick tests. However, the interpretation of the results needs to be combined with the patient's clinical symptoms because a simple increase in specific IgE does not necessarily mean there is a clinically significant allergy, and there may also be false positive cases.
Ⅲ. Oral food challenge test (needs to be carried out under the supervision of a doctor)
Principle:
The oral food challenge test is the "gold standard" for diagnosing food allergies. After excluding other factors that may affect the results (such as the patient having no other diseases and not taking drugs that may interfere with the results), the patient, under the close observation of a doctor, gradually ingests a small amount of soy products and then observes the body's reaction.
Operation process:
First, the patient needs to avoid eating soybeans and soy products for a period of time before the test (such as 1 - 2 weeks). At the beginning of the test, a very small dose of soy products (such as 1 - 5 grams) is given, and observation is carried out for a period of time (usually 1 - 2 hours). If there is no reaction, the dose is gradually increased. The whole process is carried out in a hospital or a specialized allergy detection center. The doctor will be equipped with corresponding emergency equipment and drugs to deal with possible severe allergic reactions.
Accuracy and limitations:
The oral food challenge test has high accuracy and can directly observe the patient's real reaction to soybeans. But it has certain risks because it may trigger severe allergic reactions such as anaphylactic shock, so it must be carried out under strict medical supervision. And this test is relatively time-consuming and the operation is relatively complex.
If you suspect that you are allergic to soybeans, it is not recommended to conduct detection or diagnosis by yourself. You should consult a doctor or an allergy specialist. They will comprehensively judge whether there is an allergy to soybeans based on your personal symptoms, medical history, and test results.
