Amoxicillin belongs to the penicillin class of drugs, and patients who are allergic to amoxicillin are not necessarily allergic to cephalosporins. Amoxicillin and cephalosporins are not considered to be the same type of antibiotics, and their antibacterial mechanisms of action are different. Patients with penicillin allergy can easily be allergic to amoxicillin, so a penicillin skin test can be used instead of a skin test for amoxicillin before using amoxicillin, but a penicillin skin test cannot be used instead before using cephalosporin. Patients who have a negative penicillin skin test may also be allergic to cephalosporins. Therefore, if cephalosporins are required, a skin test with the original drug solution is recommended to rule out allergy. The probability of allergy to cephalosporins is lower than the probability of allergy to penicillins.