Skin tests can be done at night. Skin test usually refers to intradermal test, which is the most commonly used specific test in clinical practice. Certain drugs are prone to allergic reactions during use, such as penicillin, tetanus and cephalosporins. In order to prevent the occurrence of allergic reactions, these drugs usually require skin sensitization tests before use. Skin test is not limited by time, you can do skin test at night, but you need to observe the results in a bright environment to avoid errors in judgment. After the skin test, the local skin will bulge a small dermatome, if the light is not enough at night, it can affect the judgment of the skin test results. In addition, after the skin test, patients should avoid rubbing or scratching with hands to avoid localized skin redness. It is also necessary to pay close attention to their own changes, such as skin itching, pimples, dyspnea and other discomforts, need to immediately ask the doctor for treatment. In case of a positive result, patients should avoid using this drug. Skin tests can be done at night, and patients are advised to go to a regular healthcare facility when they experience discomfort.