How Long Would An Allergic Reaction Take (And Why)?

Exact Answer: 15 Seconds to 15 Minutes

There is a substantial number of people living with allergic reactions. Allergies are considered to be developed, due to a genetic disorder of an individual. Everyone is aware of the causes & effects of allergic reactions, and a few allergies are quite common in many individuals.

According to a study, almost one-third of the population have some type of allergy. These allergies can have mild to severe effects. Most people tend to ignore the symptoms of allergy.

Broadly classified, allergies are of two major types: mild & severe. Most of the allergic people are under the mild category. These allergies are not life-threatening. On the other hand, a small number of people experience severe allergic issues that fall under the severe category called anaphylaxis.   

How Long Would An Allergic Reaction Take

How Long Would An Allergic Reaction Take?

An allergic reaction is given by the immune system of the body upon the entry of the allergens. Allergens are non-harmful to the majority of people. When an allergen enters the body of an allergic person, the immune system acts as if a foreign substance has entered. This gives rise to a typical allergic reaction.

You might have seen allergic people sneeze wildly. Allergic reactions & their symptoms like sneezing may take around 15 to 30 seconds. Whereas skin rashes & their symptoms may take 10 to 15 minutes. Anaphylaxis is a condition of emergency where any delay can be fatal. The symptoms can be visible within 20-30 seconds of exposure to the allergen.

Also Read:  How Long After Salt Water Flush To Eat (And Why)?

Allergies are a result of the unusual working of the immune system. It is important to know what triggers the allergic response. Once identified, one needs to distance themselves from those substances. However, the symptoms seem to differ from person to person. Irrespective of it, the time that is taken by the allergic reactions is highly dependent on the response time of the immune system.

The most common allergies are by:

  • Pollen,
  • Dust particles,
  • Food items,
  • Weather,
  • Bee sting, and many more.

Allergic reaction symptoms are:

  • Sneezing,
  • Runny nose,
  • Rashes,
  • Watery eyes,
  • Hives,
  • Itching, and many more.
Allergic Reaction
Allergic SymptomsTime
Sneezing15-30 Seconds
Rashes10-15 Minutes
Watery Eyes2-5 Minutes
Itching1-5 Minutes

Why Would An Allergic Reaction Take So Long?

The lifestyle of a person is affected by the adverse effects of allergic reactions on the body. However, this can be minimized once the allergens are identified. As long as the allergens are avoided, it doesn’t trigger the immune system.

The visible outcomes that a person suffers from an allergy are very complicated from the inside. It is not as straightforward as it looks. The duration taken by the allergic reaction depends upon the rate of antibodies produced. The number of allergens exposed to the body also plays an important role in increasing the number of antibodies

The immune system starts producing antibodies called Immunoglobulin E (IgE). These antibodies are proteins that travel in the body and promote cells to release histamines. These chemicals cause visible symptoms that can be identified.

Allergic Reaction

Most of the allergic reactions are easily reversible. As soon as the allergic reactions & their symptoms start, one can take proper medication. Medication includes immunotherapy, antihistamines, decongestants, and other medicines.

Also Read:  How Long Does A Cold Last (And Why)?

A proper preloaded kit of medicine such as an epinephrine injector is required to tackle anaphylaxis. During anaphylaxis, the allergic reaction is quick and can be fatal. Even a slight delay in medical attention to the patient can be risky.


Allergies are quite common, but this does not mean that they can be avoided. Allergies can be hereditary and can be passed on from one generation to another. There are more chances to have an allergy if some family member has already been prone to allergy.

Thanks to the advancements in the medical field, allergies are better understood. The advanced tests, medications, research on precautions, several types of allergens, types of allergies have been quite useful.

The time duration taken by the allergic reaction is highly dependent upon the type of allergy (& allergens), the point of contact, the number of allergens exposed, the reaction of the immune system, and many other factors.



Avatar of Nidhi


Hi! I'm Nidhi.

Here at the EHL, it's all about delicious, easy recipes for casual entertaining. So come and join me at the beach, relax and enjoy the food.


Leave a Reply

Your email address will not be published. Required fields are marked *