Anaphylactic shock, or anaphylaxis, is a severe allergic reaction to a substance that is perceived as a threat to the body. The allergic reaction is sudden, occurring within seconds or minutes, and encompasses the entire body. Anaphylactic shock is a rare reaction; however, it is a life-threatening condition that requires immediate emergency medical care.
Physiology
When the body is exposed to an allergen, the immune system releases a compound called histamine. When released, histamine causes blood vessels to widen and leak. A widening of the blood vessels leads to lower blood pressure and narrow airways. A leak in the blood vessels causes another decrease in blood pressure along with swelling of body tissues. In most cases, this allergic response is minor. In severe allergy cases, the body's immune system responds by releasing an excess of histamine, causing a dangerous drop in blood pressure and a severe tightening of the airways.
Causes
Most cases of anaphylactic shock are caused by an allergic reaction to food. The most common food allergies are nuts, shellfish, eggs, milk, wheat and soy, states the National Health Services. Other common cases of anaphylactic shock are caused by allergies to medications, such as penicillin, aspirin and painkillers, or allergies to insect bites or stings, according to the Mayo Clinic.
Symptoms
Symptoms of anaphylactic shock are serious and usually develop within minutes. In rare cases, symptoms can develop within 30 minutes to one hour, says the Mayo Clinic. Symptoms include hives, flushed or pale skin, swollen tongue and throat, narrowing of airways, weak and rapid pulse, nausea, diarrhea and dizziness. Because of the narrowed airways, a person in anaphylactic shock will have trouble breathing accompanied by wheezing and blue skin, due to lack of oxygen.
Treatment
Anaphylactic shock is an emergency situation and requires immediate medical attention. If the anaphylactic person is unconscious, a trained professional will administer CPR. When conscious, a person experiencing anaphylaxis will be given a shot of epinephrine, or adrenaline, immediately. The epinephrine helps to open the airways and increase blood pressure. Antihistamines and cortisone, which reduce inflammation, will be given intravenously, or through the vein. Supplemental oxygen will also be administered in order to make up for lost oxygen due to restricted breathing. Once the anaphylactic shock is stabilized, admission to the hospital will follow. Hospital admission usually lasts for 24 hours to ensure symptoms of anaphylactic shock don't return.
Preparation
In order to decrease the chances of coma or death due to anaphylactic shock, it is important for someone who has known allergies to be prepared. Medical bracelets or necklaces should be worn to alert others of specific allergies. An emergency medication kit that includes allergy medication along with an epinephrine auto-injector should be kept on the individual at all times. It is also important for the individual to inform his or her doctor of any allergies to food or medications, always check food labels and avoid areas that contain known triggers of an allergic anaphylactic response.
