Complications

Having an allergy increases your risk of certain other medical problems, including:

• Anaphylaxis. If you have severe allergies, you're at increased risk of this serious allergy-induced reaction. Foods, medications and insect stings are the most common triggers of anaphylaxis.
• Asthma. If you have an allergy, you're more likely to have asthma — an immune system reaction that affects the airways and breathing. In many cases, asthma is triggered by exposure to an allergen in the environment (allergy-induced asthma).
• Sinusitis and infections of the ears or lungs. Your risk of getting these conditions is higher if you have hay fever or asthma.