Ever know someone that if they got bit by an ant or stung by a bee they had to get a shot immediately or risk serious illness and possibly even death? What about a person that had to turn down a delicious, fresh-baked brownie because it had nuts in it? Ever walk by a field and have your eyes suddenly get red and itchy? People that can say yes to any of the above scenarios are unfortunate enough to have an allergy.
Allergies are reactions that people have when they are hypersensitive to certain things resulting in some kind of reaction by the body. Some can result in very serious reactions and even death (i.e. peanut, bee stings) while others are relatively minor and may cause a mild discomfort such as a rash on the skin, red, puffy eyes, and sneezing.
Doctors will often tell parents that they should avoid giving new born babies and infants certain foods till they get older due to the severity of some allergic reactions. Testing can be done in order to diagnose whether a person is allergic to something as well. This is often done through blood tests or by placing possible allergens on the skin to see if there is a reaction.
People can come into contact with something they are allergic to in a number of different ways. Sometimes it can be completely environmental. For example, hay fever reactions can be had when walking by a field and someone may find out they are allergic to cats just by being in a room with a cat or where a cat has recently been. Other common ways are by ingestion, i.e. food or medicine allergies, by touch, or via insect bite.
Should a person have a severe or mild reaction to something there are medicines that can alleviate or prevent an allergic reaction. Decongestants can be used to alleviate the symptoms for some allergies. Anti-histamines can be used to prevent certain reactions. Epinephrine is a hormone often used by those with peanut or bee allergies, and must be injected to keep the person from going into anaphylactic shock.