The American Academy of Allergy, Asthma and Immunology estimates that 40 to 50 million Americans suffer from one or more allergic diseases. Most allergy sufferers' symptoms are mild, including cases of hives, rashes, nausea, sneezing, runny nose or watery eyes. Some people have severe reactions to allergens that can be fatal if not treated quickly.
Dust Mites
Dust mites are too small for the naked eye to see, but they are present in many homes and workplaces. These tiny creatures feed off bacteria, fungi and dead skin cells found in common dust balls. Most people are not allergic to the mites themselves, but rather the proteins in their waste products. Bedding, mattresses, pillows, upholstery, carpets and other textiles tend to harbor these microscopic creatures. Nemours KidsHealth reports that although they are present year-round in the United States, they do not live in high-altitude areas.
Pollen
Pollen can trigger seasonal allergic rhinitis, also known as hay fever. The pollens that cause hay fever will vary from person to person and region to region and include deciduous and evergreen trees, grasses and ragweed. Microscopic pollens generated by the plants float through the air and cause the hay fever, so the time of year and the current weather will play a role in whether symptoms develop. Hot, dry, windy days tend to bring on sudden symptoms including itching, runny noses, sneezing and watery eyes.
Pet Dander
Americans love their pets, but animals can trigger allergic reactions in many people. The American Academy of Allergy Asthma & Immunology estimates pets trigger allergy symptoms in one out of 10 allergic individuals. The number may be as high as one in five for individuals with asthma. Contrary to common belief, animal hair does not trigger allergies. Even hairless dogs or dog breeds labeled "hypoallergenic" may trigger symptoms. Dander of dogs and cats contains a protein that can cause allergy symptoms. Microscopic particles carry these proteins through the air, and the people around the animals inhale them.
Food
Dr. Hugh Sampson, pediatric immunologist and president of the American Academy of Allergy, Asthma and Immunology, states that food allergies are on the rise globally, but particularly in the United States where roughly 4 percent of the population is affected. Sampson says that younger children are at the most risk, and as many as 8 percent of children under the age of 3 have food allergies. The Mayo Clinic says that milk, eggs, peanuts, fish, shellfish, soy, wheat and tree nuts such as almonds, cashews and walnuts are the biggest culprits. Mild allergic food reactions may result in nausea or vomiting. Severe reactions can quickly cause anaphylactic shock. People prone to severe food reactions should carry an epinephrine auto-injector and medical alert card.
