Anaphylactic shock is a severe allergic reaction that happens after contact with a substance that triggers an allergy, such as shrimp, peanuts, bee venom, or certain medications like antibiotics.
The symptoms of anaphylactic shock, also known as anaphylaxis, usually appear within seconds to minutes after exposure to the allergen. They may include trouble breathing, a tight feeling in the throat, and swelling of the mouth, tongue, or face.
If symptoms of anaphylactic shock occur, it is critical to go immediately to the nearest emergency room so that treatment can begin as quickly as possible and life-threatening complications can be prevented.
Symptoms of anaphylactic shock
The main symptoms of anaphylactic shock include:
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Trouble breathing
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Wheezing, throat clearing, or hoarseness
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Red, itchy hives or welts on the skin
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Swelling of the mouth, tongue, eyes, or face
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Difficulty swallowing or speaking
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Rapid heartbeat
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Dizziness or feeling faint
In some cases, anaphylactic shock can also cause abdominal pain, cramping, nausea, vomiting, diarrhea, paleness, and confusion.
These symptoms typically appear within seconds up to one hour after exposure to the allergen.
As soon as symptoms of anaphylactic shock are recognized, hospital care is needed right away to begin treatment and reduce the risk of serious complications.
How to confirm a diagnosis
The diagnosis of anaphylactic shock is made by a doctor in the hospital, based on the symptoms and history of contact with the allergen. Tests are generally not required to confirm the condition.
Diagnostic criteria for anaphylactic shock include at least one of the following: breathing difficulties, low blood pressure, fainting, incontinence, hives, swelling of the face, lips, tongue, or throat, or persistent abdominal cramps or vomiting.
Possible causes
Anaphylactic shock happens when the immune system has an extreme response to an allergen.
Substances that may trigger anaphylactic shock include:
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Medications such as antibiotics, pain relievers, anti-inflammatories, vaccines, or anesthetics
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Iodine, found in seafood and in medical products like povidone-iodine or radiologic contrast agents
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Foods such as shrimp, fish, shellfish, peanuts, milk, eggs, wheat, and soy
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Latex-containing materials such as gloves, condoms, balloons, or tourniquets used in blood tests
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Insect stings from ants, bees, hornets, or wasps
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Dust mite droppings, mold, pollen, animal fur, or saliva
Metals such as silver, nickel, or cobalt, and certain cosmetic products like perfumes, shampoos, creams, or soaps may also cause anaphylactic shock.
Not all exposures cause anaphylactic shock, but they can lead to allergic reactions. Awareness and prevention are important to reduce the risk of severe complications.
Treatment for anaphylactic shock
Treatment for anaphylactic shock must be started right away and may include:
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Injection of epinephrine (adrenaline) into the muscle
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Antihistamines and corticosteroids, such as diphenhydramine, methylprednisolone, or hydrocortisone, given by injection into the muscle or vein
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Oxygen mask to support breathing
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Cricothyroidotomy, a surgical procedure used in severe airway obstruction, where a cut is made in the throat to allow airflow
After treatment, hospital observation for several hours is often needed to monitor vital signs.
What to do after an anaphylactic shock
After an episode of anaphylactic shock, it is recommended to see an allergist to identify the substance that caused the severe allergic reaction. An allergy test may be performed for confirmation.
Once the allergen has been identified, it is essential to avoid any contact with it.
In cases where the risk of recurrence is high, or when avoiding exposure is difficult, a doctor may prescribe an epinephrine auto-injector. This device should always be carried and used at the first signs of anaphylactic shock, while waiting for emergency medical care.