The timing of allergen testing is related to the method of testing and the type of allergen being investigated, and cannot be generalized. Generally, the clinical search for allergens is mainly for type I allergic reactions. Type I allergens are detected mainly by two methods, including prick test and blood test. The prick test is a test in which the allergen is applied to the skin, and the results are usually available in 20 minutes. The blood test, in which blood is drawn and checked for specific antibodies against the corresponding allergen, is usually available within 2-3 days, but varies from hospital to hospital. If the allergen is a delayed allergen, which is more specific in the dermatology department, it is called contact allergen, which is measured by direct skin contact with the substance causing the allergy, mainly through the patch test, where the allergen is put on the body and the results are checked for 48 hours, or even 72 hours, i.e. 2-4 days before more accurate results can be obtained. In addition, it is recommended that allergy patients avoid spicy and irritating foods in their diet, hairy items such as fish, shrimp, crab, chicken, goose, beef and mutton, and pungent and fragrant things such as leek, celery, cilantro, green onion, ginger and garlic.