According to the Asthma and Allergy Foundation of America, allergies strike one in every four Americans, and is the 5th leading chronic disease in the U.S. among all ages. Unfortunately, there is no cure for allergies, but they can be managed through lifestyle changes and medication.

Allergies are caused when the immune system overreacts to an “allergen.” Allergens can be in what you eat, in the air you breathe, or on something that comes in contact with your skin. Symptoms may include coughing, sneezing, itchy eyes, runny nose, and/or a scratchy throat. Severe cases of allergy can also cause rashes, hives, low blood pressure, difficulty breathing, asthma attacks, and even death.

When an allergic reaction is triggered eosinophils (a type of white blood cell) can build up and lead to inflammation.  This is particularly troublesome for those with asthma and eosinophilic esophagitis as damage may occur to the lungs and esophagus. A CBC test can be used to monitor the level of eosinophils in the blood.