Seasonal allergies are a common part of life for many people. From sneezing and nasal congestion to itchy skin and watery eyes, allergy symptoms can range from mild to disruptive and affect everyone differently. Allergies are one of the most common chronic conditions, impacting one in three people throughout the U.S. An allergy develops when the immune system identifies a normally harmless substance as a threat and reacts to it. These substances, known as ...