Risk factors

While anyone can have an allergic reaction to penicillin, a few factors can increase your risk. These include:

• A history of other allergies, such as food allergy or hay fever
• Allergic reaction to another drug
• A family history of drug allergy
• Increased exposure to penicillin, because of high doses, repetitive use or prolonged use
• Certain illnesses commonly associated with allergic drug reactions, such as infection with HIV or the Epstein-Barr virus