Difference Between Anaphylaxis and Allergic Reaction    

Anaphylaxis and Allergic Reaction are two medical conditions sharing similar characteristics, though there are some differences between them. The key difference between them is that allergy is a reaction of the immune system against a certain substance in the environment that normally doesn’t cause problems while Anaphylaxis is a severe form of allergy. In this article, we are going to analyze these two conditions in depth.

What is Anaphylaxis?

Anaphylaxis is a severe form of allergic reaction demarcated by circulatory collapse. Symptoms typically include generalized hives, itchiness, flushing, or swelling of the afflicted tissues, wheezing, and very low blood pressure. Anaphylaxis can occur in response to any external substance to the body. Common allergens include insect bites, foods, and drugs. Foods are the most common cause in children while drugs and insect bites are more common among adults. Epinephrine (adrenaline) is the primary treatment for anaphylaxis which helps to increase the blood pressure, and it is the lifesaving treatment in anaphylaxis.

What is Allergic Reaction?

Range of allergic disease includes fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, runny nose, shortness of breath, or swelling. Most common allergens include food and pollen. Allergic tendency is contributed by both genetic and environmental factors. The underlying mechanism is immunoglobulin E antibodies (IgE), which is a part of the body’s antibody pool against pathogens or harmful substances, binding to an allergen triggering the release of various inflammatory chemicals into the blood stream.

Patch testing is used to determine if a particular substance causes an allergic reaction on the skin. Adhesive patches containing common substances causing allergy are applied on the back of the person. The skin is then examined for possible local allergic reactions, usually at 48 hours from the application of the patch.

Treatments for allergies include avoiding known allergens and the use of medications such as steroids and antihistamines. In severe reactions, injectable adrenaline (epinephrine), is recommended to prevent progression to anaphylaxis. Allergen immunotherapy includes gradual exposure of people to larger and larger amounts of allergen (sensitization is useful for allergies such as hay fever). However, it is not a popular more of treatment. Symptomatic treatment with steroids and antihistamines are more commonly used in simple allergies.

What is the difference between Anaphylaxis and Allergic Reaction?

Definition of Anaphylaxis and Allergic Reaction

Anaphylaxis: Anaphylaxis is a severe form of allergic reaction demarcated by circulatory collapse.

Allergic Reaction: Allergy is a reaction of the immune system against a certain substance in the environment that normally doesn’t cause problems.

Characteristics of Anaphylaxis and Allergic Reaction


Anaphylaxis: In anaphylaxis, low blood pressure is the remarkable feature.

Allergic Reaction: During an allergic reaction, low blood pressure is not a prominent feature.


Anaphylaxis: In anaphylaxis disease, onset and progression is very rapid, and the patient can die within minutes.

Allergic Reaction: Normal allergic reaction has a milder cause, and the mortality is less.


Anaphylaxis: In anaphylaxis, adrenaline is a must and almost always should be included in the treatment regimen.

Allergic Reaction:In normal allergic reactions adrenaline in not an essential component in the treatment.


Image Courtesy:

” “Blausen gallery 2014”. Wikiversity Journal of Medicine. DOI:10.15347/wjm/2014.010. ISSN 20018762. – Own work. (CC BY 3.0) via Wikimedia Commons 

“Signs and symptoms of anaphylaxis” by Mikael Häggström – Own work. (CC0)via Wikimedia Commons