The ABCs of Allergies　(2/2)

In the United States, experts estimate that up to four percent of adults and up to eight percent of young children have food allergies. Every year these allergies cause about thirty thousand cases of anaphylaxis, a severe reaction that requires immediate treatment.

It can result in trouble breathing and in some cases death. The National Institute of Allergy and Infectious Diseases says one hundred to two hundred people die. It says most of the reactions are caused by peanuts and tree nuts such as walnuts.

People can also be allergic to medicines. The American Academy of Allergy, Asthma and Immunology says about five to ten percent of bad reactions to commonly used medicines are allergic. In other words, a person's immune system overreacts and produces an allergic reaction. The most common reactions include skin rashes, itching, breathing problems and swelling in areas such as the face.

But the academy estimates that allergic reactions to drugs cause one hundred six thousand deaths each year in the United States alone. It says antibiotics such as penicillin are among the drugs more likely than others to produce allergic reactions. So are anticonvulsants and hormones such as insulin. Other kinds include some anesthesia medicines, vaccines and biotechnology-produced proteins.