On "The Simpsons," Bart is allergic to butterscotch, and even to imitation butterscotch. However, it's difficult to find any mention of butterscotch allergy in medical literature (however, some butterscotch chips may contain traces of peanuts, making them possibly dangerous to someone with a peanut allergy). In an episode of "Desperate Housewives," Bree's husband Rex unknowingly eats onions, to which he is allergic. He ends up in anaphylactic (life-threatening) shock and goes to the hospital by ambulance. A severe allergic reaction to onions is actually rare. In fact, allergy to onions usually only causes mild symptoms, such as itching of the mouth -- not anaphylactic shock. Foods that contain proteins more likely to cause severe allergic reactions in susceptible people include shellfish and peanuts.
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