Anaphylaxis

Anaphylaxis

Anaphylaxis is a serious and potentially deadly allergic reaction that occurs rapidly—often in a matter of seconds or minutes—after being exposed to an allergen. Common allergens are peanuts and bee stings. During anaphylaxis, the immune system produces a flood of chemicals that can send the body into shock. This results in a sudden drop in blood pressure and a narrowing of the airways, making it difficult to breathe. Symptoms may include a weak, rapid pulse, skin rash, nausea, and vomiting.

Common triggers include certain foods, medications, insect stings and latex. Immediate treatment with an epinephrine injection is essential, followed by a visit to the emergency room. If epinephrine is not available, seeking emergency medical attention is critical because untreated anaphylaxis can be fatal.

Signs and Symptoms

Anaphylaxis symptoms usually develop within minutes of allergen exposure, though in some cases, they may take 30 minutes or longer to appear. Rarely, symptoms can be delayed by several hours. The following are common signs:

  • Skin reactions such as hives, itchiness, or flushed and pale skin
  • Fall in blood pressure (hypotension)
  • Narrowing of the airways and swelling of the tongue or throat, causing wheezing or difficulty breathing
  • A weak, rapid rhythm
  • Lightheadedness, dizziness, or fainting
  • Nausea, vomiting, or diarrhea

Causes

Anaphylaxis results from a severe allergic reaction, which occurs when the immune system mistakenly identifies a harmless substance as dangerous. To combat the perceived threat, the immune system releases a surge of chemicals that lead to allergic reaction symptoms. While most allergic reactions are mild, a severe reaction can escalate to life-threatening anaphylaxis.

Common triggers

In children:

Food allergies are the leading cause, with triggers including peanuts, tree nuts, milk, fish, shellfish, sesame, wheat and soy.

In adults:

Common causes include insect stings (from bees, wasps, hornets, yellow jackets or fire ants), latex, and certain medications, such as aspirin, antibiotics, and other over-the-counter pain relievers. Intravenous (IV) contrast used in imaging tests can also be a trigger.

Exercise-induced anaphylaxis

Rarely, anaphylaxis may occur during physical activity like jogging or walking. This can be associated with eating specific foods before exercising, or working out in extreme weather conditions (cold, hot or humid). If you suspect exercise-induced anaphylaxis, consult your healthcare provider for guidance.

Unknown triggers

Sometimes, the cause of anaphylaxis cannot be identified, a condition known as idiopathic anaphylaxis. Allergy tests may help determine the underlying trigger when the cause is unclear.

It’s important to note that even mild allergic reactions in the past can develop into severe anaphylaxis with subsequent exposures. Therefore, identifying and managing triggers is essential for prevention.

Risk Factors

The following are some of the factors that can raise the likelihood of anaphylaxis:

  • Previous anaphylaxis: You are more likely to have an anaphylactic reaction if you have already experienced one. The next reactions could possibly be more severe.
  • Allergies or asthma: Individuals who already have allergies or asthma have an elevated risk of anaphylaxis.
  • Underlying conditions: Heart disease and specific medical conditions, such as mastocytosis (an abnormal build-up of mast cells), can increase susceptibility to anaphylaxis.

Complications

Anaphylaxis is a deadly condition that can cause severe complications such as the inability to breathe or the cessation of the heartbeat.

Diagnosing Anaphylaxis

In order to diagnose anaphylaxis, your healthcare provider will review your medical history and inquire about any previous allergic reactions. Questions may focus on whether you’ve experienced reactions to specific foods, latex, medications or insect stings.

To confirm anaphylaxis, your provider may recommend the following:

  • Blood tests: A blood test to check levels of tryptase, an enzyme that can remain high for up to three hours following an anaphylactic reaction.
  • Allergy testing: Skin or blood tests to pinpoint the allergen responsible for the reaction.

Since the symptoms of anaphylaxis can mimic those of other conditions, your physician may also perform additional tests to rule out.

Treatment

In the event of an anaphylactic reaction, prompt medical intervention is necessary.

  • Cardiopulmonary resuscitation (CPR): Performed if breathing or the heartbeat stops.
  • Oxygen therapy: Assists with breathing.
  • Epinephrine (adrenaline): Administered to counteract the body’s allergic reaction.
  • Intravenous (IV) medications: Antihistamines and cortisone are used to minimize airway inflammation as well as to enhance breathing.
  • Beta-agonists (e.g., albuterol): Helps ease respiratory symptoms.

Emergency Steps

If someone shows signs of anaphylaxis, such as shock (pale, clammy skin; weak, fast pulse; difficulty breathing; confusion; or unconsciousness), follow these steps straightaway:

  • Dial 911 or seek emergency medical assistance immediately.
  • Use an epinephrine auto-injector if there is one. Press the device firmly into the individual’s thigh.
  • Have them lie down with their legs elevated.
  • Check for pulse and breathing and administer CPR and other first aid measures if necessary.

Epinephrine Auto-injector

Persons at a high risk of anaphylaxis should always have an auto-injector with them. This device delivers a single dose of epinephrine when pressed against the thigh.

Key tips:

  • Replace the auto-injector before it expires to ensure it works effectively.
  • Learn how to use the device and also teach those around you.
  • Use the auto-injector as soon as possible to prevent the reaction from worsening and possibly save a life.

Long-Term Management

  • Immunotherapy: For individuals allergic to insect stings, allergy shots may reduce sensitivity and prevent severe reactions.
  • Avoiding triggers: Minimize exposure to known allergens whenever possible.
  • Carry epinephrine: Always have an epinephrine auto-injector readily available, and know how to use it in case of an emergency.

While there’s no cure for the immune system dysfunction that causes anaphylaxis, these steps can help manage the condition and reduce the risk of future attacks.

Prevention

Avoiding allergies that cause severe responses is the only approach to prevent anaphylaxis. Other precautions include:

  • Wearing a medical alert ID: Put on a necklace or bracelet that states your allergies to specific medications or substances.
  • Keep an emergency kit handy: Always keep prescribed medications on hand, including an epinephrine auto-injector. Regularly check its expiration date and replace it as needed.
  • Inform your healthcare providers: Let all your providers know about any medication reactions you’ve had.

For insect allergies:

  • Put on long-sleeved clothing.
  • Avoid walking barefoot on grass.
  • Refrain from using perfumes, colognes and scented lotions and wearing bright-colored clothes.
  • Instead of swatting at the stinging insects, remain calm and slowly move away.

For food allergies:

  • Pay close attention to food labels, even those you buy frequently, as manufacturing procedures may change.
  • When dining out, inquire about how dishes are prepared and check for hidden allergens since even trace amounts can trigger a reaction.

Being prepared

Despite precautions, accidental exposure to allergens can still occur. You can thus respond effectively by recognizing signs and symptoms of anaphylaxis in such cases. It is also important to have a plan to address symptoms fast.

Conclusion

Knowing that everyday food can trigger a severe allergic reaction can be frightening, but there are steps you can take to reduce the risk. If you experience symptoms of anaphylaxis, use your epinephrine auto-injector immediately, and then call 911 or head to the nearest emergency room. Quick treatment is crucial and can prevent fatality.

Always carry your auto-injector with you and do your best to avoid known triggers. If managing your allergy symptoms feels overwhelming or if you suspect you’ve experienced anaphylactic shock, consult your GP for guidance.

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