health sectionhealth sectionMany people experience adverse reactions to a medication at some point in their lives. About 5 percent to 10 percent of these reactions are caused by a drug allergy. An allergic reaction happens when your immune system overreacts to the proteins in the drug. Allergic reactions to sulfonamides, or sulfa drugs, are common. Signs of a sulfa allergy include a rash and hives, though more serious symptoms such as Stevens-Johnsons Syndrome can also occur.
