The condition usually appears in early childhood, but can develop at any age.
It must always be treated as a medical emergency, requiring immediate treatment and urgent medical attention. Anaphylaxis can involve breathing, the cardiovascular (heart and circulation) system and the gastrointestinal (digestive) tract.
Anaphylaxis occurs when a person’s immune system reacts to the presence in the body of a usually harmless substance such as a food or chemicals from an insect bite resulting in an extreme body reaction.
In this case, the body’s immune system is over-reacting in response to what it sees as a foreign invader or allergen entering the bloodstream. This provokes the release of massive amounts of histamine and other chemicals.
The blood vessels widen, which leads to a sudden severe lowering of blood pressure and constriction of the airways in the lungs. The reaction can begin within minutes but sometimes the reaction can occur hours after the event.
The onset of anaphylaxis can be deceptive – it may be signaled by severe, but non life-threatening reactions. They can, however, become increasingly dangerous very quickly with or without subsequent exposure to the allergen. The time frame from the onset of the first symptoms to death can be as little as a few minutes if the reaction is not treated.
Further, even if symptoms subside after initial treatment, they can return as much as eight hours after exposure. It is also important to know that symptoms do not always occur in the same order, even in the same individuals.
