Lone star tick is the culprit and cause for meat allergy in the East Coast. The galactose-alpha-1,3-galactose, or alpha-gal for short, has affected more than 1,500 Americans, making them allergic to meat and the numbers may be more, according to CNN.

Researchers believe that the allergy might have come from tick larvae.

"Perhaps there is an organism in the tick's saliva that makes a person allergic to the alpha-gal sugar in mammalian meat," said Dr. Scott Commins, assistant professor of medicine at the University of Virginia in Charlottesville.

Anaphylaxis is the deadliest form of an allergic reaction. The entire body, or parts of the body, reacts violently to the antigen (external factor that causes a reaction). The throat and tongue swells up sometimes that leads to difficulty in breathing.

"People will eat beef and then anywhere from three to six hours later start having a reaction; anything from hives to full-blown anaphylactic shock. And most people want to avoid having the reaction, so they try to stay away from the food that triggers it," said Dr. Scott Commins.

The link that this tick is causing the allergy hasn't been proven yet.

"It's hard to prove. We're still searching for the mechanism," Commins said to ABC News.

Allergies occur when the body reacts abnormally to a substance. The body has a tendency to go overboard in protecting us from otherwise safe things like peanut butter or soy. Most people who are allergic to certain things are due to genetic reasons. A full-blown allergic reaction during adult life is uncommon.

The allergy doesn't occur immediately but shows signs only after 3-6 hours.

"It's very atypical as food allergies go. Most food allergies occur very quickly. And it's also a bit unusual to see adults develop a food allergy," said Dr. Stanley Fineman, president of the American College of Allergy, Asthma and Immunology.

Recently a study from Yale had suggested that allergies are a useful way of keeping humans out of the environments that are unsuitable for them.