Avoidance of food is a dietary contraindication. When you suspect that your hives are caused by a food allergy, avoidance is the key. However, the success of avoidance depends on whether you can find the real “hairy” food. If you can identify the “hairy substance” and then avoid it, you will get twice the result with half the effort. How to find the “hair”? There are many methods, and in the medical field, it is generally known as double-blind controlled oral stimulation test, that is, the “gold standard”, which is valuable, but not everyone can do it, and requires certain professional skills to do so. Here are two simple methods, although not very precise, but everyone can do, just a little attention, careful observation is. One method: Start with the suspected “hairy” or the most common “hairy” food. Although there are many foods that can cause hives, 50% of them are caused by the following foods: eggs, milk, peanuts and other nuts for children, and fish, shrimp, nuts and peanuts for adults. Take milk as an example. Stop using milk for 1~2 weeks, replace with soy milk, children’s urticaria or eczema stop or significantly reduce, that is, immediately or resume the application of milk, if urticaria or eczema recurrence or significantly aggravated, then again stop using milk, such as urticaria or eczema again disappeared or significantly reduced, then you can be basically sure that milk for children’s urticaria or eczema “hair products”. On the contrary, if there is no significant change in the skin lesions, regardless of the discontinuation or recurrence of the disease, it should be considered that it is not related to milk and is not a “hair product”. All other foods can be used to determine whether they are “hair products” or “non-hair products” by applying the pattern of “stop using (lesion reduction) – use again (lesion aggravation) – stop using again (lesion reduction again)”. “Non-emergent”. It should be noted that if you are sure that milk or egg is a “hair product”, you should stop using all foods containing milk or egg. Method 2: Try a simple “non-antigenic” food for two weeks. This method is suitable for older children or adults. If the condition improves significantly after 2 weeks on the “no antigen” diet, the skin disease can be considered to be related to food allergy. If a food is added and the condition worsens, the principle of one of the methods should be applied (stop using it – then stop using it again) to further confirm, and if it is definitely a “hairy food”, it should be avoided as much as possible. If there is no significant change in the skin lesion after 2 weeks of using simple food, it should be considered that it is not related to food allergy, and other “hair” causes should be looked for. The “no antigen” simple foods are as follows: one meat: lamb or turkey; three vegetables: potatoes, carrots, cauliflower (cabbage or bean sprouts); one fruit: usually pears; non-wheat, corn-based grains: usually rice. Others: water, salt, sugar, but condiments such as vinegar and soy sauce should be avoided.