Environmental allergies may affect up to 40% of children and most allergies first appear during childhood. Allergy symptoms may include nasal congestion, runny nose, dark circles under the eyes, throat irritation, cough, and eye irritation. Often, children with allergies may be diagnosed with repeated colds or sinus infections. Allergies may also contribute to the development of infections, such as repeated ear or sinus infections. They can also worsen asthma symptoms. Specific allergies and sensitivities can be diagnosed through a simple blood test and can be treated effectively with medications to alleviate symptoms.