]]>

Definition

Anaphylaxis is a severe, sometimes life-threatening, allergic reaction.

Causes

Substances that cause anaphylaxis are often called allergens or triggers. Common triggers include:

  • Medications (eg, antibiotics, seizure medications, muscle relaxants)
  • Insect stings or bites
  • Vaccines]]>
  • Foods and food additives, especially eggs, peanuts, seafood, cow's milk, soy, and tree nuts
  • Blood products
  • Latex products (eg, gloves, medical tubing, condoms)

Allergic Reaction to Medication (Hives)

© 2009 Nucleus Medical Art, Inc.

Some triggers, like dyes used in x-ray procedures, can cause a reaction similar to anaphylaxis.

]]>

Risk Factors

These factors increase your chance of developing anaphylaxis. Tell your doctor if you have any of these risk factors:

  • Previous mild allergic reaction to the substances listed above
  • History of eczema]]> , ]]>hay fever]]> , or ]]>asthma]]>
  • Children who have certain conditions, such as ]]>spina bifida]]> and urogenital defects (due to the heavy exposure to latex they have during multiple surgeries)

]]>

Symptoms

The symptoms of anaphylaxis usually occur within minutes after exposure to an allergen, but can occur hours later. Symptoms may be mild or very severe, including death. They include:

  • Hives]]> and itching
  • Swelling, redness, stinging or burning, especially on the face, mouth, eyes, or hands
  • Lightheadedness, caused by a drop in blood pressure
  • Obstruction of the nose, mouth, and throat
  • Severe respiratory distress
  • Chest tightness, shortness of breath, wheezing
  • Nausea, vomiting, cramping, ]]>diarrhea]]>
  • Heart ]]>arrhythmias]]>
  • Convulsions
  • Low blood pressure, ]]>shock]]> ( occurs in 30% of cases)

]]>

Diagnosis

Diagnosis is based on the symptoms. The doctor will suspect anaphylaxis if you have symptoms and have been exposed to a likely allergen.

Treatment

Anaphylaxis is a medical emergency that requires immediate medical treatment, including:

  • Epinephrine (adrenaline) injection—makes blood vessels constrict, relaxes the airway, stops itching and hives, and relieves gastrointestinal cramping
  • Other medications—corticosteroids and/or antihistamines may be given after the epinephrine to decrease inflammation and improve breathing.
  • Bronchodilators—to improve breathing
  • Intravenous fluids
  • Oxygen
  • Cardiopulmonary resuscitation]]> (CPR)—may be necessary in severe cases when anaphylaxis leads to cardiovascular collapse. Severe anaphylaxis may require ]]>mechanical ventilation]]> until swelling is brought under control.

If you are diagnosed with anaphylaxis, follow your doctor's instructions .

Prevention

Avoiding substances that trigger anaphylaxis is the best prevention. In addition:

  • Allergy shots can decrease the risk of anaphylaxis and reduce the severity of the reactions to certain triggers.
  • Wear a medical alert jewelry that lists your allergies.
  • Tell your doctor or dentist about your allergies before taking any medication. When possible, ask that medications be taken as a pill. Allergic reactions can be more severe with injected medications.
  • Keep self-injectable epinephrine (eg, Epi-Pen, Twin-ject) with you at home, work, in the car, and when you travel. Be sure family and friends know how to use the kit too.
  • Make sure the school nurse knows about any allergies your child has.
  • If allergic to insect stings, wear protective clothing when outside.
  • Always remain in the doctor's or dentist's office 30 minutes after receiving an injection. Report any symptoms right away.