An inappropriate response by an individuals immune system to a normally harmless substance is known as an allergic reaction
An allergic reaction symptoms include localized swelling, blotchy skin, itching, sneezing and runny eyes and nose. Allergic reactions can be triggered by medications, non-organic substances (for example latex) or natural products; foods, animals and insects.
In most cases allergic reactions are merely irritating, posing no medical threat and resolve without treatment.
Anaphylactic shock (from the Greek for 'non-healing') is a severe life threatening allergic reaction that needs immediate medical attention. This type of allergic reaction is treated with an injection of adrenaline. Individuals who have previously experienced such a reaction usually carry an 'adrenaline pen' that can inject a life saving dose of adrenaline in the event of similar reaction occurring again.
Additional medical conditions: