Tuberculosis skin test refers to tuberculin test, the difference between redness and swelling and hard nodules after the test is that redness and swelling are non-specific and hard nodules are specific allergic reactions. 1. Redness and swelling: redness and swelling of the skin after the tuberculin test is a normal phenomenon caused by the tuberculin skin test solution. Attention should be paid to the injection site, can not scratch with hands, do not wash with soap and water, in order to avoid infection and inflammation. Patients should pay attention to light diet, eat less chili, shrimp and other stimulating foods, local redness and swelling will slowly subside. 2. Hard nodules: hard nodules after tuberculin test are usually infected with tuberculosis, or once infected with tuberculosis. If presenting infection is considered, anti-tuberculosis medication should be given early and regularly, such as isoniazid tablets, which is conducive to the recovery of tuberculosis. During the course of treatment, symptoms of liver and kidney impairment such as elevated transaminases may occur, if they do, please seek medical attention promptly. If there are abnormal results of tuberculosis examination, it is recommended to consult a doctor in time to clarify the cause of the disease with the help of a doctor and carry out targeted treatment or therapy. The use of drugs need to follow the doctor’s instructions, do not self-medication.