Anaphylactic reactions

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Anaphylactic reactions or anaphylaxis are abrupt, systemic, potentially severe and dangerous allergic reactions. This type of reaction necessitates immediate medical attention to prevent it from progressing.

What are the causes of anaphylactic reactions?

Anaphylactic reactions are typically triggered by the following:

  • Insect stings
  • Latex
  • Medications such as penicillin
  • Certain foods particularly seafood, eggs and nuts

Remember that a reaction can be triggered by any allergen. Just like with other allergic reactions, anaphylactic reactions do not usually occur after the initial exposure to the allergen but can occur after the next exposure.

Anaphylactic reactions
During emergencies, the doctor will administer epinephrine that is injected under the skin, into a vein or into a muscle.

Nevertheless, many do not even recall their first exposure. Any allergen that triggers anaphylactic reactions in an individual is likely to trigger that reaction on future exposures unless preventive measures are observed.

What are the symptoms?

Anaphylactic reactions usually start within 15 minutes upon exposure to an allergen. It is rare for reactions to occur after an hour. The symptoms tend to vary, but every individual has the same symptoms every time.

  • Rapid heart beat
  • Feeling uneasy and agitated
  • Drop in the blood pressure that results to fainting
  • Tingling sensations
  • Dizziness
  • Itchy and flushed skin
  • Runny nose and sneezing
  • Coughing
  • Hives
  • Swelling of the tissues beneath the skin
  • Difficulty breathing and wheezing due to the constriction of the throat and/or airways
  • Nausea and/or vomiting
  • Abdominal cramps and diarrhea

An anaphylactic reaction can progress rapidly that the individual collapses, ceases to breath, experience seizures and lose consciousness within 1-2 minutes. A reaction can be deadly unless immediate medical attention is provided.


Avoidance of the allergen is the ideal prevention. Individuals who are allergic to unavoidable allergens can greatly benefit from long-term allergen immunotherapy.

Those who have these reactions must also bring along an auto-injectable epinephrine and antihistamines for immediate relief. If the individual is exposed to a trigger or he/she starts to develop symptoms, he/she must inject a shot and take an antihistamine.

In most cases, this treatment stops a reaction momentarily. Nevertheless, once a shot is given, it is vital to head straight to the nearest emergency department for further monitoring and care. In addition, it is recommended to use a medical alert bracelet.


During emergencies, the doctor will administer epinephrine that is injected under the skin, into a vein or into a muscle. If the breathing is significantly impaired, a breathing tube is inserted into the windpipe via the mouth or nose or through a small-sized incision in the skin of the trachea.

Low blood pressure often returns normal once epinephrine is given. If it remains low, fluids are given intravenously to increase the blood volume. In some cases, medications that causes the blood vessels to constrict are given to increase the blood pressure.

Antihistamines and H2 blockers are administered intravenously until the symptoms of anaphylactic reactions subside. A corticosteroid might be given to prevent the symptoms from recurring.

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