In some foreign countries such as the United States and the United Kingdom, it is true that skin tests are not required when using penicillin injections. In China, however, the need for a skin test before using penicillin has become common knowledge for almost everyone, and it is known that penicillin can cause severe anaphylactic shock.

Why penicillin causes anaphylactic reactions

First, let's look at why some people develop penicillin allergies. The structure of penicillin is composed of two parts, one is "β-lactam ring" and the other is "hydrogenated thiazole ring", the structure of hydrogenated thiazole ring is extremely unstable, and it is easy to be cleaved, rearranged and polymerized, and when this structure changes, the β-lactam ring connected to it will be separated from it, and then go to bind the specific IgE (which is the antibody mediating the type I allergic reaction), thus the penicillin will be allergic. When this structure changes, the β-lactam ring that is connected to it separates from it, and then binds to specific IgE (this is the antibody that mediates type I allergic reaction), thus inducing a "rapid-onset allergic reaction", leading to severe anaphylactic shock or even death.

If severe allergic reactions can occur with penicillin, why aren't skin tests done abroad?

This is because penicillin skin test reactions are prone to false positives, and false negatives.

Studies have found that half or even more false positives exist in penicillin skin tests. This is due to subjective reasons or objective conditions, such as: the disinfectant solution used to wipe the skin during the skin test may enter the skin and produce allergy, creating the false impression of penicillin allergy; also, if the injection is too deep, or if too much of the skin test solution is used, false positives may be produced, such as reddening of the skin; and there is also a lack of control tests to exclude the false-positive criterion.

Some studies have shown that patients with negative skin tests can still have rapid-onset allergic reactions to penicillin.

Therefore, in foreign countries, experts believe that the penicillin skin test is unreliable in predicting whether an allergic reaction to penicillin is likely to occur, and that false negatives may cause doctors to take penicillin use lightly, while false positives may deprive many patients of the option of penicillin treatment. The procedure for penicillin use abroad is to ask the patient for a history of allergy, which is taken very carefully, including the patient's past allergy history, what drugs or foods he or she has had allergic reactions to, and the symptoms and manifestations of the allergic reaction. By asking the history of allergy to weigh the need to use penicillin, if the patient has previously used penicillin severe allergic reactions, generally will not be used, if the previous use of minor allergic reactions such as skin rash, in principle, can be used, but the relevant first aid measures are well prepared.

It is true that some foreign countries do not need to conduct a skin test when using penicillin, and these countries include the United States, the United Kingdom, Germany, etc. In our country, it is basically common knowledge that a skin test must be conducted before using penicillin. In our country, before using penicillin, skin test must be carried out, this is basically a common sense known to everyone, why is it not necessary to carry out skin test when using penicillin in foreign countries, but it is necessary in our country?

Penicillin allergic reaction includes rash, dermatitis, serum sickness, hemolytic anemia, and in severe cases, anaphylaxis can occur, which is very dangerous. The incidence of penicillin allergic reaction is about 0.7%-10%, related to personal constitution, from the incidence of know span is very little, and once anaphylactic shock is very dangerous, so China's various guides, instructions for the use of medication, Pharmacopoeia, and drug manuals, etc. have clearly stipulated that the prescribing of penicillin should be inquired in detail about the patient's history of food and drug allergy as well as the family history, and the use of the pre-skin test must be carried out by a negative skin test can be used only after the skin test. The skin test is negative before use.

Penicillin allergic reaction is thought to be caused by its degradation product penicillin thiazole protein and other antigen sensitization. It is also believed that this is related to the purity of penicillin, we all know that foreign and domestic pharmaceutical process is different and the standard of drug requirements are also different, compared to foreign requirements than the domestic more stringent, so in the clinic will find that some of the drugs started to use imported did not occur adverse reactions, but from the use of imported to domestic drugs, adverse reactions often may appear. Overseas may be because of the high purity of the drug, the chances of allergic reaction is greatly reduced, so do not carry out skin tests.

The above is only a personal opinion, not as a basis for the use of medication, please use the medication under the guidance of a physician, any questions or views are welcome to leave a comment at the bottom of the article.

The authoritative interpretation of Pharmaceutical Affairs, unauthorized reproduction, plagiarism will be punished.

Penicillin allergy is a type 1 hypersensitivity reaction characterized by a degree of reaction that is not related to the dose of penicillin. Therefore, the theoretical basis and foundation of the skin test, which is a microdose to test whether the human body will develop allergic symptoms, does not exist, and therefore, no one in developed countries does this skin test. Even foreign clinicians cannot understand our routine practice. But here's the point! Why does the Ministry of Health make skin testing mandatory? Because our penicillin purification technology is still extremely low, the medicinal penicillin contains rich "high polymer" (impurity) this impurity is very easy to cause a variety of hypersensitivity reactions to our body, and this is related to the dose. Therefore, we use domestic penicillin to skin test and different hospitals may use different manufacturers of drugs, if you want to change a hospital in the treatment of drugs need to do a skin test, the same hospital to change the same manufacturer of different batches of products sorry you do a skin test again. Look at the Americans 80 years ago can be purified technology we now can not do, so we really have nothing to be proud of. By the way, North China Pharmaceutical is China's largest penicillin production enterprises, its quality is also the benchmark, but exported abroad can only be used as raw materials and veterinary drugs.

Really. I worked in '94, and a colleague in one of my departments had his mother-in-law, wife, and daughter all get green cards, and because we were a judiciary, my colleague didn't want to quit his job, so he wanted to mix it up until he retired and then go to the US. This colleague accumulated a large number of transfer slips every year to offset the vacation time he took to visit his family in the United States, so he was on duty almost every day for his colleagues in the same hospital. In 1994, he came back from the United States and said that he had a bad cold in the United States. When he went to the hospital, the doctor said to use penicillin, and he asked the doctor if he needed to do a skin test, and the doctor said that penicillin did not need to do a skin test for a long time, and that it was the safest and most effective one. I asked him why, and he said that the American doctors said that the degree of purification is high, so there is no need for a skin test.

In a word, domestic penicillin has low purity. China is a big producer of penicillin, but the sad thing is that the exported penicillin can only be used to produce veterinary drugs. China's drug standards are low, leading some foreign manufacturers to deliberately lower their standards to produce drugs specially for China. When it comes to domestic generic drugs, the 2007 revision of the Measures for the Administration of Drug Registration standardized the approval process for generic drugs to a certain extent. However, the problem of low standards has still not been completely solved. For example, whether or not to choose the original drug as the target of the generic drug determines the efficacy of the generic drug, but the Measures allow that when the original drug is not available, the listed domestic generic drug can be used as a reference and then copied, and the efficacy can reach 90% of the reference drug. This has resulted in the production of factory A with reference to the original drug, the potency of 90%; factory B with reference to the production of A, the potency of 90% X 90%, factory C with reference to the production of B, factory D with reference to the production of C, the quality of the latter drugs, can only be disastrous.

The use of penicillin in foreign countries does not require a skin test, this and the country's management of drugs, production and purification process, drug research and development investment are closely related.

As for the domestic why need skin test, look at the domestic production of penicillin manufacturers, the threshold of the low is simply outrageous, as for the reason why, we have their own heart on the good.

Also, about 5% of patients will have a skin test negative penicillin allergic reaction, so even those with negative skin tests should not be taken too lightly.

I have a friend used to work in Inner Mongolia Bayannur City Linhe District federal pharmaceutical intermediates manufacturer, in the fermentation workshop engaged in disinfection work, the production of amoxicillin, and then we know that the federal pharmaceutical production of amoxicillin effect than the mainland various pharmaceutical companies to produce similar products how much better? According to some friends said that the production process is the same, how could the difference be so big, we know that in the mainland non-the same batch of penicillin or more than three days without the use of penicillin need to be re-skin test, it can be clearly seen in each batch of the quality is not the same, simple can be understood as the same production process due to a variety of reasons to retain impurities are different, so don't take the same process to say things, not only penicillin, cephalosporins is not so, but the same process, the same process, the same process, the same process. Cephalosporin is not the same? Roche's Rochefin, or ceftriaxone sodium, needs a skin test, and the domestic ceftriaxone sodium? So the rest is up to you to make up your own mind.

The main reason for penicillin allergy is because of the impurities in the preparation, which used to be high due to the poor preparation process, and the cost would be much higher if the impurity content was reduced. This is the reason why there is a significant difference in the price of domestic and imported and joint venture preparations. Do not say that the imported price is higher because the cost is higher. Some of the domestic penicillins and cephalosporins do not require skin tests anymore. This is due to the improvement of the level of technology, as well as the consistency evaluation of drugs, that is, the comparison with the original drug.

As with oral amoxicillin, Federal Pharma's content is 99.9%, mainland production is an order of magnitude worse. So also don't compare a few dollars of omeprazole to AstraZeneca's omeprazole, it's meaningless.

This is the same as foreigners don't drink boiled water, we don't have to look like foreigners. Foreigners do not use skin test may be related to racial genes, diet, environment (for example, a lot of people can not adapt to milk). The percentage of penicillin allergy is still very high, without skin test is likely to be hung up.

As a medical student, I also learned about the situation, many foreign places do not skin test penicillin, there are two reasons, one is related to the processing and purification of penicillin drugs, and the other is the management system!

Processing purification, which is related to the quality of drugs, it must be said that in Europe and the United States, the processing of penicillin purification is really doing well, this country still need to make progress! Management system, our country for the management of drugs is notoriously strict! This also determines why our country to penicillin users skin test! Some people do not quite believe my words, I will give an example, not related to medicine, such as in the civil aviation passenger aircraft, many foreign countries can use cell phones, only a small part of our country can, which is why our civil aviation safety is very high an important reason!