Why did the doctor give you a skin test before penicillin injection? What's the effect?

Penicillin is commonly used in clinic because of its good curative effect and low drug price. However, there are great risks in using penicillin, and medical accidents related to penicillin injection that lead to patients' timely death emerge one after another. Different people have different tolerance to penicillin, and some patients will have a strong allergic reaction due to penicillin injection. Therefore, skin test must be carried out on patients before penicillin injection to avoid accidents when penicillin is injected in large quantities.

The reason of penicillin skin test is that the reaction mediated by penicillin is type I hypersensitivity. After an allergic patient is injected with penicillin, the mast cells in the body will be sensitized. When a large amount of penicillin enters the body, the antibodies involved in allergic reaction will combine with mast cells under the action of cytokines, and mast cells will synthesize and release sensitized particles, causing allergic reactions. Due to the strong contraction of bronchial smooth muscle and airway stenosis, patients will have respiratory asphyxia, vasodilation, vascular permeability changes, plasma protein escape, severe shock and cerebral syncope.

Efficacy of penicillin skin test A small dose of penicillin skin test will not cause a strong allergic reaction in the body, but it can also detect whether the patient is allergic to penicillin. After the skin test of penicillin injection, if there is a red lump on the arm larger than 1 cm, the patient feels itchy and dizzy, indicating that the patient is intolerant of penicillin. Doctors need to change the treatment plan and use other drugs to treat patients. Therefore, penicillin skin test is a guide for doctors to use drugs, which avoids the possible risks caused by direct use of penicillin injection, avoids unnecessary medical disputes, and will not lead to the tragedy of saving lives.

Penicillin skin test has become common sense, a mandatory requirement of hospitals, a general principle for doctors to use penicillin and a responsibility for patients' life and health. In addition, because penicillin is easily converted into penicillanic acid under long-term illumination, nurses should follow the principle of preparing penicillin solution now, so as not to change the properties of penicillin solution and affect the results of penicillin skin test.