Allergies arise when our body’s defense system begins to react to everyday things such as pollen. People who have allergies have a hyper-alert immune system that overreacts to an allergen. These reactions may cause symptoms such as itchy eyes, sneezing, coughing, rashes and hives. Allergic reactions can lead to asthma, hay fever, sinusitis, stinging insect reactions, food and drug allergies, allergic rashes, and hives. These conditions are best treated by an allergy specialist.