Allergies are brought on when the immune system acts as though foreign substances are more harmful than they really are.
According to the Centers for Disease Control and Prevention, eight types of food account for more than 90 percent of allergic reactions in affected individuals. The eight: milk, eggs, peanuts, tree nuts, fish, shellfish, soy and wheat.
However, some people react to some very unusual allergens. Here are nine of the weirdest allergies.