Drug allergy is an adverse drug reaction. It is a war of elimination launched by our immune system by mistaking drugs for enemies. Some people even have allergic reactions to anti allergic drugs. In fact, nearly 90% of drug allergies in life can be predicted in advance. Listen to what pharmacists say. Allergy medicine can cause allergy. After playing football on the lawn in the afternoon, Xiao Wang had a rash on his back in the evening. He was itchy and scratched all the bumps. He took a taxi to the emergency department of the hospital in the middle of the night and was diagnosed as "acute allergic urticaria". After taking an anti allergic medicine, Xiao Wang felt chest tightness, dizziness, general weakness, difficulty breathing, and blood pressure dropped. The doctor quickly judged that it was the rapid type allergic reaction caused by anti allergic drugs, and dealt with it decisively and gave immediate rescue. After recovering, Xiao Wang sent out a soul torture: "what I am using is obviously a medicine to treat allergies. Why can it cause allergies?" Examples of allergy to antiallergic drugs like Xiao Wang are rare, but they also exist. This is because the impurities introduced in the production process of drugs and the substances produced after the transformation of anti allergic drugs in vivo may be potential allergens. Moreover, the mechanisms of action of antiallergic drugs are various, including direct combination and inhibition of allergy, reduction of the release of allergic substances, improvement of self adaptability and alleviation of allergy, etc. an antiallergic drug often only focuses on one aspect and cannot block all channels that cause our allergy. Therefore, the use of antiallergic drugs may still lead to allergy. Don't carry the drug allergy when these symptoms appear. It is an adverse drug reaction. It is a war of elimination launched by our immune system mistaking drugs for enemies. What exactly is a drug allergy? Drug allergy may cause local or systemic rash, and may be accompanied by pruritus, swelling, redness and fever. "Rapid type" allergy is more serious, and even dyspnea, unconsciousness and hypotension may occur. Drug allergy may occur quickly after drug administration, or may occur several days after drug administration, or even after drug withdrawal. Professional doctors or pharmacists are required to make a judgment. Professionals make a judgment after comprehensively considering the time of taking medicine, type of occurrence, discontinuation of medicine and other relevant factors. What symptoms do you need to go to the hospital? If you have difficulty breathing, chest tightness, chest pain, dizziness, swelling of face, lips and tongue after using a new drug, please call 120 to the hospital immediately. In case of urticaria (itching, swelling red patches, which will subside within a few hours), severe stomach pain or vomiting, fever, blisters, etc., please also go to the hospital in time. Most drug allergies can be prevented in advance through allergy tests and other tests. 85% to 90% of drug allergies can be predicted based on pharmacological knowledge of drugs. Therefore, if you have known drug allergy, please inform the medical staff of the drug allergy information. And carefully fill in their allergy history on the cover of the outpatient medical record, including drug allergy history, food allergy history and some special allergic diseases. Drugs sometimes contain more than one ingredient and may also contain more than one drug name, so it is sometimes not obvious whether there are allergic drugs in the prescription. If you are allergic to a specific drug, you may also be allergic to