Usually, allergies cause sneezing, watery and itchy eyes, a runny nose, itchy skin, and rash. Some allergic reactions, called anaphylactic reactions, are life threatening. Symptoms suggest the diagnosis, and skin testing can help identify the substance that triggers the allergy but does not predict the severity of a future reaction. Avoiding the trigger is best, but if it is impossible. Find out about allergies, including typical symptoms, common allergies, when to get emergency medical help and allergy testing and treatments. Type I reactions underlie all atopic disorders (eg, atopic dermatitis, allergic asthma, rhinitis, conjunctivitis) and many allergic disorders (eg, anaphylaxis, some cases of angioedema, urticaria, latex and some food allergies). The terms atopy and allergy are often used interchangeably but are different: Allergy symptoms can present in varying ways and degrees, depending on the allergy type and severity. Here’s everything you need to know. Prevention Preventing allergic reactions depends on the type of allergy you have. General measures include the following: Stay away from known triggers. Do this even if you get treatment for your allergy symptoms. If, for instance, you're allergic to pollen, stay inside with windows and doors closed when pollen is high. Substances that come into contact with the skin, such as latex, are also common causes of allergic reactions, known as contact dermatitis or eczema. [35] Skin allergies frequently cause rashes, or swelling and inflammation within the skin, in what is known as a wheal and flare reaction characteristic of hives and angioedema. [36] A 21-year-old male arms during an allergy skin test. A. Learn about different types of allergies, allergic reactions, their types, symptoms, and severity. An allergy is a reaction by your immune system. Substances that cause reactions include pollen and food. Find the full list of allergies and symptoms. Allergic reactions are symptoms that happen after you touch, inhale or eat something you’re allergic to. Common causes include foods, plants, medications and pets. Pulmonary Function Tests For suspected allergic asthma, lung function tests such as spirometry may be conducted to assess breathing capacity and airway responsiveness. Treatment of Allergies: Restoring Balance While there is currently no cure for allergies, treatments aim to reduce symptoms, prevent reactions, and improve quality of life.