8 Dangerous Food Allergies.

1. Tree nuts: typically among the most severe food allergies, causing swift and dangerous reactions. You may be allergic to one or more hard-shelled nuts, including walnuts, pecans, almonds, cashews, Brazil nuts, and hazelnuts. 

2. Peanuts: often go hand in hand with other nut allergies—and can be just as risky. Peanuts can appear in unlikely places, such as ground-up in candies.

3. Shellfish: Crustaceans such as crab, lobster, and shrimp contain a compound called tropomyosin, which often triggers severe reactions. Shellfish allergies tend to develop in adulthood. Interestingly, some of these adults may have been exposed to cockroaches as children.

4. Fin Fish: Fish with fins—including salmon, tuna and cod—contain allergens such as parvalbumin. In addition, fish that isn't refrigerated properly can cause an allergy-like reaction called histamine toxicity.

5. Milk: Cow, goat, and sheep milk can cause severe allergic reactions in children. Some outgrow it, while others must avoid dairy their entire lives.

6. Eggs: If you have an egg allergy, a specific protein in egg whites sets off your immune system. But because yolks often contain bits of the whites, too, it's not safe to eat any egg products at all—including low-cholesterol egg substitutes. 

7. Wheat: Celiac disease, eating foods containing gluten causes damage to the intestines. But wheat can cause immediate allergic reactions, too. Fortunately, wheat allergy is rare. 

8. Soy: Soybeans contain several proteins that can set off severe allergic responses. You may be able to eat some processed foods that contain soy, since different preparation methods can alter these proteins.