A mustard allergy is less common in the United States, than in Europe, but not unheard of here. There have been cases recorded of severe anaphylactic reactions to mustard. There are many recorded cases of mustard allergies seen in France, Spain, and Sweden. There is a strong association between a mustard allergy and a mugwort pollen sensitivity. Mustard allergy is now the fourth leading cause of food allergy in French children, after milk, eggs, and peanuts! Many cases of mustard reaction do experience anaphylaxis! Mustard allergy may be hard to diagnose because the natural skin irritation of the product makes scratch testing difficult to achieve accurate results. The best way to confirm an allergy to mustard is with a RAST test, or an oral challenge.
Mustard is found in condiments, cheese and egg dishes, curries, sausages, deli meats, salad dressings, barbecue sauces and some topical ointments for pain relief.