If you get a bacterial infection, strep throat, a breathing disorder, or an ear infection your doctor may have put you on antibiotics. Antibiotics such as penicillin are used to kill the bacteria and improve overall health. Antibiotics are used to cure a wide range of illnesses and relieve the symptoms in most diseases. However, some people have allergic reactions to penicillin and have to be placed on other equally effective antibiotics. Another popular antibiotic is amoxicillin, which is commonly used in place of penicillin.

Allergic reactions to antibiotics such as penicillin may appear as a rash and not immediately noticed. Another symptom is swelling to various parts of the body, especially the face and throat area. Sometimes breath disorders appear such as shortness of breath. This is a more severe allergic reaction. Anaphylactic shock is another more severe allergic reaction, which is caused by the airway swelling and becoming obstructed. This will occur shortly after taking an antibiotic. Allergic rashes may not develop until several days after beginning the antibiotic.

For rashes that develop from taking an antibiotic without swelling taking an antihistamine usually relieves the symptoms. Your doctor can also give you another form of antibiotic that is in a different class or family. If you are allergic to penicillin always, inform your doctor and your dentist. Many dentists use antibiotics such as penicillin to cure any infections prior to dental surgery. You should also be aware that many antibiotics now have generic equivalents that can be just as risky to take.