Patient's question:
The purpose of preparing penicillin skin test solution only when needed: Previous treatment history and effectiveness: Test results and examination findings: What kind of assistance is needed: The purpose of preparing penicillin skin test solution only when neededDoctor's answer:
Extrinsic allergic reaction. It has been determined that the aqueous solution of penicillin, when placed at 37°C for 24 hours, shows an increase in the content of penicillenic acid by approximately 200 times compared to the time of preparation. During storage, the pH value of the aqueous solution gradually decreases, with the rate of increase being negatively correlated with temperature, drug concentration, and storage time. An increase in solution pH tends to promote the polymerization of penicillin, leading to the formation of high-molecular-weight allergenic polymers. If used as a skin test solution, it not only exhibits false positive reactions but also easily induces anaphylactic shock. Therefore, after preparation, the skin test solution should be stored at low temperatures and should only be used on the same day.