Allergy is defined as an immune system response to a substance that is otherwise harmless. An estimated 1 in 5 Americans suffers from allergies, which can cause a variety of cold-like symptoms or a skin rash.

Allergy Causes & Symptoms

Allergies are caused by a variety of different factors. There are seasonal allergies such as hay fever that result from grasses, weeds, pollen, and mold; food allergies; allergies to pet dander; and allergies to medications, chemicals, and environmental irritants. They occur when your body’s immune system creates antibodies in response to a substance it incorrectly deems as a harmful invader. This causes inflammation of the skin, sinuses, airways, or digestive system.

Symptoms vary depending on the allergen. Hay fever, or allergic rhinitis, causes cold-like symptoms such as congestion, runny nose, and itchy or watery eyes. Food allergies can cause a tingling sensation in the mouth, swollen lips and tongue, and hives. Skin allergies result in itchy skin that may appear red, flaky, or peeling. Some allergies – bee stings, for instance – can cause anaphylaxis, a life-threatening reaction that may cause you to go into shock. Signs include lightheadedness, shortness of breath, a rapid or weak pulse, skin rash, nausea or vomiting, swollen airways, and loss of consciousness. A person experiencing anaphylactic shock should receive immediate medical attention.

Allergy Treatments

Avoiding the allergen trigger is the best method of preventing allergy attacks. Medications are available to reduce your immune system’s reaction and provide symptom relief; drugs such as antihistamines, decongestants, and corticosteroids can all prove helpful. Those whose allergies do not respond to medical treatment may be given allergy shots (immunotherapy) in an effort to build up a tolerance to the offending substance through regular injections given for several years.