Allergies affect millions of people around the world every day. Whether you're allergic to dust in the air or peanuts in your food, allergies can be a big health problem. Even if you don't have allergies, you probably have family or friends who do. Allergies can be annoying or they can be dangerous. Itching and sneezing may be the least of your troubles when it comes to allergies You hear about allergies on TV and read about them online. But...