The Nature of Anaphylaxis

Anaphylaxis is an acute allergic reaction due to the systemic effects of histamine release. Depending on the person's immune system, this reaction can develop from a few minutes to over several hours. It affects several areas and organs of the body including the skin, gastrointestinal system, respiratory system, heart and vascular disease, and the central nervous system. Anaphylaxis' deadliness can be attributed to its ability to affect multiple systems at the same time.

The full-blown syndrome can include hives (urticaria), and angioedema with hypotention and bronchospasm. The upper and lower respiratory tracts are normally the first one to be affected causing shortness of breath and difficulty in breathing.

This allergic reaction can occur in all age groups so no one is spared. Depending on the allergen, anaphylaxis that occurs in infants and children are normally caused by food ingestion. While past exposure to an allergen is essential for its development, reactions occur even when there was no documented prior exposure to any allergy-causing agent. Under normal circumstances, patients will react to a first exposure to an allergen such as an antibiotic or insect sting. The subsequent exposure can usually lead to anaphylaxis. The elderly have the greatest risk of mortality from this disorder due to the presence of preexisting diseases.