Welcome to the Allergy & Immunology group of SmartGuy.com. Feel free to interact with other professionals from across the world. You can find professionals, find deals on services, find professionals who might barter, or simple post questions, comments, or suggestions. Allergies, or allergic diseases, are made up of conditions caused by hypersensitivity of the immune system to something in the environment that usually causes little or no problem in most people. These diseases might include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Immunology is a branch of biology that covers the study of immune systems in all organisms.