Anaphylaxis: Physiologic Progression and Overview
Anaphylaxis is, by its very nature, a rapid-onset reaction. Patients suffering from an anaphylactic reaction will often go into anaphylactic shock and die if the condition is not quickly reversed. The onset of anaphylaxis is triggered by some outside cause-- common causes for anaphylaxis include bee stings and peanut consumption, for instance (Huether and McCance, 2008). Anaphylaxis can be triggered by both immunologic and nonimmunologic mechanisms (Huether and McCance, 2008). When mediators are released from certain white blood cells that are used in both immunologic and nonimmunologic mechanisms, the body reacts by presenting the symptoms that are commonly associated with a severe allergic reaction. This may include the swelling of the face, including the nose and throat; when the nose and throat swell, the individual will have trouble breathing (Huether and McCance, 2008). If the airway is not restored, death will occur (Huether and McCance, 2008).
When anaphylaxis is caused by the immunological mechanism, immunoglobulin E activates sensors and receptors in basophils and mast cells. This activation causes the mediators of the inflammatory response to be released; histamine is one of these mediators. When these are released, the body responds by increasing vasodilation and the contraction of the smooth muscles in the throat (Huether and McCance, 2008). Immunological mechanisms are the kind of mechanism most likely to affect the average citizen; nonimmunologic mechanisms are caused by foreign substances that physically degrade the cells responsible for releasing mediators (Huether and McCance, 2008).
Because anaphylactic events are multisystem events, they occur very quickly. The multisystem response in the body can be extremely effective when the body has to react to something harmful; however, most immune responses are to something that would generally be harmless, like pollen or bee stings (McPhee et al., 2003). This means that the body’s systems can break down normal routines very quickly; once these routines are interrupted (like breathing, for instance) the rest of the body’s systems will also rapidly shut down as well (McPhee et al, 2003).
Whenever breathing is compromised and no epinephrine is prescribed to the patient, emergency care is necessary for the patient. Emergency care should certainly be administered in any case where the patient cannot breathe; if the patient is not aware of any severe allergies, intensive care is likely needed. For patients who are aware of their allergies and carry an epinephrine pen, emergency care might not be needed, although follow-up care is likely to be necessary. If a patient is suspected of having an allergic reaction that is severe but does not seem to be impairing his or her trouble breathing, then medical intervention may be necessary, but emergency intervention is not necessarily so.
Age should have a significant impact on how an anaphylactic reaction is treated. Children may be unaware that they even have an allergy-- they have not been around very long, after all, and it takes exposure to the allergen for parents or children to realize that they are allergic to something. The very old also may not have the strength necessary to survive anaphylaxis. However, for adolescent and adult individuals, the presence of an airway should dictate whether or not an individual needs emergency care. Behavior, again, is another issue; people who are constantly exposing themselves to new and exotic things may be at higher risk for anaphylaxis, because they will be interacting with potential allergens that are foreign to them.
References
Huether, S., & McCance, K. (2008). Understanding pathophysiology. St. Louis, Mo.: Mosby/Elsevier.
Jacobsen, R., & Gratton, M. (2011). A Case of Unrecognized Prehospital Anaphylactic Shock.Prehospital Emergency Care, 15(1), 61-66. doi:10.3109/10903127.2010.519823
McPhee, S., Lingappa, V., & Ganong, W. (2003). Pathophysiology of disease. New York: Lange Medical Books/McGraw-Hill.
