Anaphylaxis is a sudden, potentially life-threatening allergic reaction. The symptoms may begin mildly but quickly become severe, often in a matter of seconds to minutes; occasionally, though, the symptoms develop gradually over a 24-hour period. The more rapidly the symptoms begin, the more severe they generally are. Anaphylaxis may occur again the next time a person is exposed to an allergen (allergy trigger). The first exposure to a trigger generally lays the groundwork for anaphylaxis by creating hypersensitivity. Anaphylaxis should always be considered a medical emergency, and you should seek help right away. It is estimated to be responsible for 500 deaths each year.
Signs and Symptoms
- Itching (often the first symptom), redness, hives, swelling, sweating
- Swelling in the nose or throat, hoarseness, wheezing, difficulty speaking, trouble breathing, chest tightness
- Abnormal heart rate or rhythm, shock, heart attack
- Stomach cramps, nausea, vomiting, diarrhea
- Loss of bladder or bowel control, an urgent feeling of needing to go to the bathroom
- Tingling, headache, light-headedness, feeling disoriented or feeling a sense of doom, fainting, seizures
What Causes It?Anaphylaxis occurs when the immune system overreacts to an allergen that you have encountered at least once before. Occasionally, through a different mechanism, an anaphylactic-like reaction (called anaphylactoid reaction) occurs with the very first exposure to the allergen. Symptoms are the same for both anaphylaxis and anaphylactoid reactions. Symptoms develop when cells release substances that are meant to protect you against the allergen.
Examples of anaphylaxis triggers include:
- Aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen), and prescription opiate pain medications (such as codeine); people with asthma and nasal polyps tend to be at greater risk for an anaphylactoid reaction to these drugs
- Foods, such as nuts, shellfish, egg whites, and berries; those who react to ragweed may also react to chamomile tea
- Insect bites or stings
- Egg-based vaccines
- Ingredients in some allergy skin tests, allergy shots, and vaccines
- Blood transfusions
- Latex (as in condoms, rubber gloves)
- Food coloring and preservatives (such as tartrazine, also known as FDC yellow dye No. 5)
- Although rare, athletes may have an anaphylactoid reaction to exercise after eating certain foods, such as celery, shrimp, apples, squid, wheat, hazelnut, or chicken; this reaction is thought to be related to endorphins
Who's Most At Risk?The following factors may increase your risk for anaphylaxis:
- Initial exposure to the allergen by injection (intravenous medication)
- Frequent exposure to the allergen, particularly if frequent exposure is followed by a long delay and then a reexposure
- Taking beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, or angiotensin II receptor blockers (ARBs)—medications used to treat heart disease or high blood pressure
What to Expect at Your Provider's OfficeYour healthcare provider will perform an exam, ask about any contact you may have had with possible allergens, and conduct blood or urine tests, a chest X ray, allergy tests, or other tests.
- To help prevent anaphylaxis: Avoid anything known or suspected to have triggered a previous allergic response.
- See an allergist for testing and treatment if any allergies are known or suspected.
- Take medicines by mouth instead of by injection whenever possible.
- If you have a history of anaphylaxis, carry a syringe loaded with epinephrine to inject immediately after exposure to a known allergen or at the first sign of a reaction. Healthcare providers can suggest a kit and provide instruction. Close family, friends, and caregivers should be taught to use the kit, too. Also, wear a Medic Alert bracelet to alert others that you have a history of this condition.
Get emergency medical care right away to maintain breathing, blood pressure, and heart function and to reverse the reaction.
Epinephrine is the drug of choice and should be given right away. Once at the hospital, additional drugs, including antihistamines and corticosteroids, may be used to control symptoms and prevent delayed relapse.
Surgical and Other Procedures
For breathing trouble, healthcare providers may need to open the airway with an endotracheal tube and possibly connect a ventilator. Other procedures may be necessary as well to stabilize blood pressure.
Complementary and Alternative Therapies
Anaphylaxis always requires standard emergency medical care. For the most part CAM therapies are inappropriate for treating an anaphylactic reaction. That said, they may help prevent allergic responses, including anaphylaxis. Some CAM approaches may also lessen the severity of any allergic reaction and may improve non-life-threatening symptoms of anaphylaxis. Specific nutrients, herbs, and acupuncture show promise. Be aware, however, that like prescription drugs, some nutraceuticals and botanicals can cause allergic reactions, including anaphylaxis.
NutritionOmega-3 Essential Fatty Acids
Omega-3 essential fatty acids have anti-inflammatory properties that may help protect against the extreme reaction of anaphylaxis. There was a lower death rate from anaphylactic shock in animals on a high omega-3 fatty acid diet compared to those on a high omega-6 diet. How this translates to humans is not known at this time. Quercetin & Other Flavonoids
Naturopathic doctors have recommended that people with known allergies take quercetin (a naturally occurring flavonoid) before being exposed to allergens. This should lessen the severity of the allergic response. If you are susceptible to allergies you might want to consider taking quercetin supplements or eating foods high in flavonoids (such as fruits and vegetables) on a regular basis. Animal studies appear to support this traditional use of quercetin.
Vitamin C is thought to enhance the activity of quercetin.
Animal studies suggest that zinc may help protect against gastrointestinal symptoms (stomach cramps, nausea, vomiting, or diarrhea) that sometimes accompany anaphylaxis.
Several studies have investigated the effects of medicinal plants traditionally used in Asia to prevent or treat allergic reactions. Results from animal studies on the effects of medicinal plants traditionally used in South Korea suggest that the plants may help prevent anaphylaxis and other allergic responses in susceptible individuals. These herbal remedies include:
- Sweet chestnut tree (Castanea crenata) — used in Asian countries to treat whooping cough and lacquer poisoning; inhibited skin and blood vessels reactions related to anaphylaxis in animal studies. Quercetin is the active component.
- Spreading sneezeweed (Centipeda minima) — used in Traditional Chinese Medicine for anti-inflammatory and anti-allergy purposes; appears to inhibit the release of histamine, a substance that causes many common allergy symptoms. Contains flavonoids as one of the active components.
- Danshen root (Salviae miltiorrhiza) — used traditionally for treatment of allergies; inhibited skin related allergic reactions in rats.
- Asian rose spp. (Rosa davurica) — traditionally used to regulate immune response; inhibited anaphylaxis in an animal study.
- Hardy orange (Poncirus trifoliata) — used traditionally for treatment of allergies; animal studies have shown inhibition of anaphylaxis.
- Skullcap root (Scutellaria baicalensis) — thought to have anti-allergy activity.
- Licorice root (Glycyrrhiza glabra or G. uralensis) — thought to have anti-allergy activity.
- Reishi mushroom (Ganoderma lucidum) — thought to have anti-allergy activity.
Consumer Alert: Although this happens much less frequently with plant-based substances than with pharmaceutical preparations, there are certain herbs for which there have been rare reports of allergic reactions, including:
- Arnica flower (Arnica montana)
- Artichoke leaf (Cynara scolymus) — in those with an allergy to artichokes
- Blessed thistle herb (Cnicus benedictus)
- Cayenne pepper (Capsicum spp.)
- Cinnamon bark (Cinnamomum verum)
- Dandelion root or herb (Taraxacum officinale)—may trigger a reaction in those with latex allergy
- Echinacea (Echinacea purpurea)
- Fennel oil and fennel seed (Foeniculum vulgare)
- Ginkgo biloba leaf extract
- Poplar bud (Populus spp.) — may trigger a reaction in those with salicylate sensitivity
- Psyllium seed (Plantago spp.)—allergic response more common with powder or liquid form
- Yarrow (Achillea millefolium)
Prognosis/Possible ComplicationsWithout proper treatment, anaphylaxis can be deadly. Most people who receive proper treatment do well, however. Once you have anaphylaxis, you will not necessarily have it again even with exposure to the same allergen. But the risk is high, so do your best to avoid the inciting substance. Drugs classified as beta-blockers, monoamine oxidase inhibitors, ACE inhibitors, and ARBs may worsen anaphylaxis or interfere with treatment; if you have a history of anaphylaxis, you may want to check with your physician or pharmacist to find out if you are on one of these medications.
Following UpSymptoms that started early may continue or new symptoms may set in later. Therefore, hospitalization may be needed for at least 24 hours. For a severe reaction, providers may monitor heart function or admit patients to the intensive care unit.
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