Myth: Wearing gloves will protect you from poison ivy.
"Leaves of three, let them be," runs the standard advice on how to avoid poison ivy and its equally villainous cousins, poison oak and poison sumac. But those who are allergic to this relative of the cashew — many as 85 percent of all Americans — find that no amount of armor or vigilance can protect them.

The chemical that gives these plants their poisonous reputation is an oily resin called urushiol. And what makes it truly diabolical is that it can hitchhike on clothing, dog's fur, even garden tools. If you come into contact with poison ivy, wash the oil off (preferably with brown soap and water) within 20 to 30 minutes, before it soaks into the skin. Since the residue can remain potent for a year or more, scrub tainted items as well.

Myth: People who are allergic to shellfish are actually allergic to the iodine they contain.
Some people who are allergic to seafood avoid certain skin medications and diagnostic medical tests that use iodine because they fear an allergic reaction. But there is no connection between allergies to fish and shellfish and allergies to iodine. Allergies to fish and shellfish are caused by the protein in them, not the iodine.

Myth: Many people are allergic to milk.
Milk allergy is most common among infants and is usually outgrown in adulthood. When adults react adversely to milk — from cramps, gas, and diarrhea — symptoms are often mistaken for an allergic reaction. This is actually a condition known as lactose intolerance — inherited trait caused by the body's lack of an enzyme, lactase, needed to break down lactose, the sugar in milk or milk products.

Like food allergies, intolerances are adverse reactions to food, but unlike food allergies, they don't involve the immune system. (In cases of lactose intolerance, adults may use supplemental lactace — e.g., Lactaid — or consume dairy products from which lactose has been removed. Consultations with a nutritionist may help in identifying which supplements and which products are safe to use).

Myth: Natural ("organic") foods are nonallergenic.
Limiting your diet to organic food is no guarantee that you'll avoid food allergies. In fact, some of the most allergenic foods are "natural," unprocessed foods: cow's milk, eggs, peanuts, wheat, soybeans, fish and shellfish, and tree nuts. Combined, these foods account for up to 90 percent of all allergic reactions. Allergies are caused not by chemicals related to growing the food, but by proteins in the food.

Myth: Allergy shots don't work.
While immunotherapy may not work for all allergies and all people, it has been shown to be effective for allergies to insect venom 98 percent of the time, and for hay fever about 85 percent of the time. In some cases, immunotherapy can actually trigger an acute allergic reaction, but if the therapy is properly administered, these risks can be reduced.

Myth: Moving to the Southwestern states will cure allergies.
For allergy sufferers, there is simply no safe haven. While desert regions have no maple trees or ragweed, they do have plenty of other plants that produce pollen, including sagebrush and cottonwood, ash, and olive trees. Relocating to such a region may offer relief for a few months, but a fresh crop of allergies to local plants is likely to develop before long.