Allergic rhinitis typically results from two conditions: family history/genetic predisposition to allergic disease and exposure to allergens. Allergens are substances that produce an allergic response. Children are not born with allergies but develop symptoms upon repeated exposure to environmental allergens. The earliest exposure is through food — and infants may develop eczema, nasal congestion, nasal discharge, and wheezing caused by one or more allergens (milk protein is the most common).
