Allergic disorders are one of the most common chronic diseases among children. After a child is exposed to an allergen, the body builds up immunities to fight the seemingly dangerous substance. The next encounter with the substance could result in an allergic response, which, depending on the allergy could produce vomiting or diarrhea; swelling and hives; or itchy, watery eyes, and a drippy nose. Food allergies are quite common in children, especially in infants. Common allergy-causing foods include eggs, wheat, soy, cow's milk, and peanuts. Introducing foods gradually into your child's diet can help you assess any reaction and know which food is causing it. Respiratory allergies can also be found in children. Pets, dust mites, and molds are the most common contributors to allergies in the young. Look for symptoms such as nasal itching and congestion; sneezing; sniffling; irritated or itchy eyes; or breathing through the mouth. If you think your child might have allergies, talk to a healthcare provider. Not only can you ease the uncomfortable symptoms, you can also prevent long-term problems.