Allergy

Allergies occur when your immune system overreacts to a substance that is normally harmless, such as pollen, dust mites, or certain foods. When you come into contact with an allergen, your immune system produces antibodies that trigger the release of histamine and other chemicals in your body. These chemicals can cause inflammation, itching, and other symptoms.
 
Some common allergens include pollen from trees, grasses, and weeds; dust mites; animal dander; mould spores; insect stings; and certain foods such as peanuts, tree nuts, milk, eggs, and shellfish.
 
Allergy symptoms can range from mild to severe and may include:

• Sneezing
• Runny or stuffy nose
• Itchy or watery eyes
• Skin rash or hives
• Swelling of the lips, tongue, or throat
• Difficulty breathing
• Anaphylaxis (a life-threatening reaction that requires immediate medical attention)

• Allergy testing can also help you:
• Determine the severity of your allergies
• Identify cross-reactive allergens (substances that cause a similar immune response as the allergen you're allergic to)
• Plan immunotherapy (a treatment that can help desensitize your immune system to specific allergens)
• Types of Allergy Testing