Do you have onion allergy?

Onions are used worldwide to prepare food. Food is indeed incomplete without onions. When the prices of onions are high it becomes a great headache for people and governments around the world. Here we are going to discuss onion allergy in detail.

About onions

Onions are used nearly in every household in the world. It is used in one form or other. It is used as raw or used in cooking various dishes and curries.

For most of the population food is indeed incomplete without adding onions in it.

What is onion allergy?

Onion allergy is a type of food allergy. We know allergy is an abnormal immune response to a very common part of our environment. So when you consume onion or onion containing products and if you get an abnormal immune response so that you suffer it is called an onion allergy.

How common is onion allergy?

Compared to the large number of population consuming onions worldwide there is a very small proportion of the population that suffer from onion allergy.

There is no known exact number but it is estimated that less than 1 percent of the population may be suffering from onion allergy.

What are symptoms of onion allergy?

Onion allergy can manifest in very mild and though rare very severe forms of allergy.

Oral allergy syndrome

Oral allergy syndrome is a form of allergy which occurs in a few minutes of consumption of the allergen as a food. It represents symptoms of oral cavity or perioral region.

It presents like itching inside the mouth and on the palate and throat. There may be swelling of lips and tongue with redness.

Oral allergy syndrome can be associated with other manifestations of allergy.

Mild symptoms

Mild symptoms that may come within few minutes to few hours of consuming onions are as follows:

  • Running and stuffy nose, cough
  • Itching in nose and soft palate and throat
  • Hives and itching on skin
  • Abdominal pain and loose motions
  • Vomiting may occur in some people

Severe symptoms

  • Severe symptoms are those that need immediate medical attention or they may be life threatening.
  • Difficulty in breathing
  • Dizziness
  • Severe abdominal pain
  • Loss of consciousness
  • Rapid or slow heartbeats
  • Low blood pressure
  • Anaphylaxis

Other associated allergies

Other plants that grow from bulbs can also cause allergy to people who are allergic to onions. They include:

  • Tulips
  • Wild onions
  • Lilly onions
  • Rock onions
  • Daffodils

Which food can cause onion allergy?

Any food that contains onion can cause onion allergy to people who have a tendency of onion allergy. In many countries almost each dish contains onions. They include:

  • Salads
  • Onion curry
  • Paratha with onions
  • Onion uthappam
  • Onion dosa
  • Omelette
  • Chicken, meat and vegetable broths
  • Some types of pizza with added onion in topping

How to treat onion allergy?

This allergy is treated depending on how severe the manifestations are. For mild symptoms home remedies or no treatment may be needed.

For symptoms those do not subside by their own need treatment in following form:

  • Antihistamines: These are antiallergic medicines. They stop or reverse the action of histamine which is a chemical secreted by your immune system as abnormal response causing allergic symptoms. Some of them include hydroxyzine, cetirizine, promethazine, bilastine etc.
  • Moisturizers and aloe vera: They are not antiallergic but they help to reduce the itchy sensation of the skin at the hives.
  • Bronchodilators: For severe cases who have allergy with asthma like bronchospasm and difficulty in breathing, these bronchodilators like salbutamol may help to reduce the symptoms. They can be given orally or by nebulization and in some cases by injection.
  • Corticosteroids: Corticosteroids are useful in treatment of allergy. They suppress the immune response and they have anti allergic action too. They can be given orally or typically as a cream or by injection.
  • Epinephrine: If someone has got a severe allergic reaction and it is life threatening then epinephrine is the most effective life saving medicine. It is given by injection.

When should you see your doctor?

If the allergic symptoms are severe and beyond the limit you can tolerate you better see your doctor.

Following are the symptoms that suggest you should see your doctor:

  • Severe itching on skin
  • Hives on large surface if the skin
  • Severe abdominal pain and multiple loose motions
  • Vomiting 
  • Swellings of lips
  • Difficulty in breathing
  • Loss of consciousness and dizziness
  • Severe cough
  • Running stuffy nose not subsiding with home remedies

How to diagnose onion allergy?

Your doctor asks you about the history of food intake and symptoms. Your doctor examines you clinically and gets a clue about this allergy.

Primary history and physical examination just gives a clue about the possibility of onion allergy. As the symptoms are similar in all kinds of food allergies your doctor may suggest you some tests to get a diagnosis confirmed.

Some of these tests include Serum IgE levels, skin prick test and elimination of the food.

Currently there is no effective test to confirm the diagnosis of the onion allergy. Elimination and reintroduction helps to confirm the allergic status. Your allergy specialist may guide you regarding that.

How to prevent allergic reaction to onions?

Only best way to prevent onion allergy is stopping exposure to onions. Those who have onion allergy should stop eating onions and plant products that grow from the bulb like tulips.

Some of those who are allergic to onions may tolerate onions in cooked form like curry. The decision should be taken in consultation with an allergist.


Onion allergy is a rare form of food allergy. We don’t see many patients of onion allergy at least here in India. Like any food allergies it can cause symptoms described above.

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