Garlic Allergy Archives - Lifelab Testing

Onion Allergy Guide

An onion allergy occurs when your body mistakes onions for harmful substances. This, in turn, triggers the immune system to release antibodies to fight the “harmful” substance, and that’s when we witness onion allergy symptoms such as itchiness, vomiting, trouble breathing, and others. Onions are a common ingredient in salads and all cooked meals. It is hard to come across a restaurant or home where onions aren’t used as a primary ingredient in making stews, curries, and stir-fries. This is why it can be challenging to manage an onion allergy.

When suffering from onion allergy, different people get affected in varying ways. For example, one may get a reaction from smelling or touching onions or consuming onions, whether raw or cooked. While some people get reactions from only smelling, touching or eating raw onions (raw onion allergy), others get the same symptoms from cooked onions. Onions are part of the genus allium, which also consists of shallots, leeks, garlic, and chives. If you’re allergic to onions, it is possible to get the same reaction with other plants in the allium family. Sometimes, it may not be an allergic reaction but rather a sensitivity. This cross-reactivity is because these plants contain similar internal makeup, which the immune system can mistake for onions, producing the same immune attack resulting in onion allergy symptoms.

Not all alliums are edible; others are ornamental (inedible) and may trigger a reaction in some people through touch. If you’re allergic to onions, this means that you’ll react to all types of onions. For example, you’ll also suffer from a red onion allergy and a spring onion allergy. There won’t be any exceptions to the types of onions you’ll react towards.

Onion allergy symptoms

A woman holding her stomach.

Symptoms of onion allergy vary from one person to the other regarding mildness and severity. Once you smell, consume or touch onions if you’re allergic, you can expect symptoms to show up immediately or within a span of two hours. There are, however, others who may not experience the allergy symptoms for a few more hours. If you’re allergic to onions, you will experience a few of these symptoms that may be internal or external. These common symptoms of onion allergy include:

  • Itching and tingling in the mouth.
  • Hives or rashes all over the body.
  • Nausea and vomiting.
  • Swelling of lips, tongue, lips, face, or throat.
  • Difficulty breathing.
  • Nasal congestion.
  • Stomach pain.
  • Diarrhoea.
  • Gas.

The above symptoms often are mild and can be easily managed by home treatment. However, if you experience severe gastrointestinal issues, it is wise to visit a doctor. It is common for the symptoms to stop once the onions have left your body. In rare cases, however, onion allergy can result in life-threatening symptoms. Anaphylaxis associated with onion allergy has been reported before after consuming raw onion {1}. When one experiences anaphylaxis, there is a dire need to immediately access medical help, as this condition can easily take one’s life. There are specific symptoms you can witness that will help diagnose anaphylaxis. These are:

  • Confusion.
  • Dizziness.
  • Trouble breathing.
  • Low blood pressure.
  • Loss of consciousness or fainting.
  • Sweating.

Upon getting urgent care, a doctor will prescribe an Epinephrine pen (EpiPen). One should always carry this in person in case there are any accidents and anaphylaxis occurs. If you’re with someone and you can see they’re suffering from anaphylaxis, use an EpiPen if they have one and still rush them to the emergency room for observation. Observation is essential since these symptoms can recur after a few hours, so it’s best to stay under the doctor’s care.

Onion and garlic allergy

If you’re suffering from an onion allergy, it is common to find that you’ll have the same reaction to garlic. These two ingredients are from the same genus (allium), which means the proteins in these foods are similar, and the body mistakes one for the other. This confusion that goes on in the immune system is known as cross-reactivity. You may also find that you’ll have the same allergic reaction to other alliums like chives, shallots, leeks, and scallions. The cross-reactivity level for different vegetables in this genus varies amongst different individuals.

Onion Intolerance

Our Complete Intolerance Test Box.

The most common and well-known reaction to onions is intolerance. Onion intolerance often comes with many gastrointestinal symptoms. Often with onion intolerances, you may find that you have an underlying condition that is leading to all the gastrointestinal mishaps. In such cases, you’ll need treatment for the core ailment, which could eliminate the intolerance. However, in other cases, you’ll find that your doctor won’t be able to see any underlying conditions that could be leading to symptoms similar to the ones we’ve mentioned. It can be difficult to determine which food is causing an intolerance, as symptoms can occur days after consuming the problem food. To be sure which food item is causing symptoms, you could take an Intolerance Test. Our complete intolerance test looks at reactions to onion, garlic and 157 other items.

Onion Allergy Testing

If you have a reaction every time you consume onions, you should see your doctor, give them your history, and explain your symptoms. If you’re experiencing allergy symptoms but are unsure what is the cause, you may benefit from taking an allergy test. An allergy test will check your sample against all common allergens in your food and immediate environment then we’ll send you a list of the foods you need to avoid because you’re allergic.

Our allergy test is ideal since you don’t have to make a doctor’s appointment or wait in their office for hours on end to know what’s causing your symptoms. You can order easily online, get delivery within three days, take a sample, and once you send it back you’ll have your results within seven days via mail. With this test, you don’t have to stop working because we’ll take care of everything else while you have an uninterrupted life.

Foods that can cause onion allergy

When suffering from an onion allergy, you must avoid alliums, including shallots, garlic, chives, mugwort tea, leeks, and scallions. Avoiding all of these is the easiest way to prevent getting any symptoms. However, it can be very difficult to avoid onions since they’re in many processed, prepared, and packaged foods. When reading labels under the term ‘seasonings’, you’ll often find that alliums fall into that category. Always read labels carefully; if you’re unsure about the components, call the manufacturer, and they will let you know. You can, however, avoid foods with unclear labels.

It is also important to note that the FDA doesn’t require manufacturers to list onions as an allergen. However, manufacturers are required to list all ingredients. If the ingredient list doesn’t seem to tell you all you need to know, it is safe to pass it up and only deal with fresh ingredients rather than pre-packaged foods. By doing so, you’ll be taking extra care of your body since you’ll know every ingredient that goes into your meal. It is common to find alliums in foods like:

  • Flavoured cheese.
  • Salsa or Pico de gallo.
  • Flavouring packets.
  • Broths.
  • Frozen or pre-made pizza crust.
  • Frozen entries.
  • Crackers.
  • Premade soups and sauces.
  • Deli meats.
  • Frozen foods.

If you’re generally allergic to alliums, you’ll also have a reaction to flowering amaryllis plants, which are primarily ornamental alliums and various varieties of lilies. Be extra careful when contacting these types of flowers, as they may cause a reaction if you’re extra sensitive.

Onion allergy treatment

When you have an onion allergy, there are various ways you can manage it at home. These include:

  • Epinephrine: This autoinjector is used in treating anaphylaxis that doctors prescribe.
  • Hydrocortisone cream: Topical use can help reduce itching and inflammation.
  • Aloe Vera: If you have itchy hives, aloe vera can help soothe the redness that comes with itching, even though it can’t help histamines level in your blood.
  • Antihistamines: You can find these available as sprayed medications or oral. This medication blocks histamine production, reducing or eliminating minor allergy reactions like nasal congestion, hives, and itching.
  • Albuterol sulphate inhaler: This bronchodilator helps increase airflow through the bronchial tubes.

Even though the above forms of treatment can soothe your immediate symptoms, the best way to treat allergies is by avoiding these trigger foods. In this case, you will need to avoid onions and some alliums, if not all. Even though avoiding these will be hard at first, you will also enjoy a symptom-free life which is better than rushing to the emergency room every time. You can easily enjoy your meals without alliums and onion allergy symptoms.


  1. Arena, A., Cislaghi, C., & Falagiani, P. (2000). Anaphylactic reaction to the ingestion of raw onion. A case report. Allergologia et immunopathologia, 28(5), 287–289.

Garlic Allergy and Intolerance Guide

Garlic is a bulbous plant that is used to enhance the taste of many savoury dishes, in all traditional cuisines around the world. Garlic has a pungent smell and a savoury flavour that it adds to meals. However, if you have a garlic allergy, the mere inhalation or its aroma can cause reactions all over your body. Garlic belongs to the allium family, meaning that if you’re allergic to garlic, you may also experience reactions to other spices like chives, leeks, and shallots. Garlic allergy and onion allergy are commonly linked because most patients experience an allergy to both bulbs as they contain specific similar allergens {1}. Garlic allergy is relatively uncommon compared to garlic intolerance, but it still does exist and can be life-threatening. If you’re allergic to garlic, this means that consuming raw or cooked garlic will cause the same reactions, and it’s only best to avoid this spice. Within this guide, we will discuss both garlic allergy and intolerance, including symptoms and ways of testing.

Causes of garlic allergy

Garlic allergy, similar to other allergies, occurs when the body comes in contact with a foreign substance, and your immune system reacts to it. When you have a garlic allergy, your immune system assumes that this substance is “harmful” even though, in reality, it’s not. When your immune system releases antibodies to fight something that’s not typically harmful to the body, it’s what we refer to as an allergic reaction. Food allergies are a specific type of allergy that can be triggered by even the smallest amount of the trigger object or food. Food allergies affect around 8% of children and 3% of adults.

The most common types of allergies are shellfish, peanuts, tree nuts, milk, and eggs. Compared to these, garlic allergy is among the rare allergies people suffer from. According to most clinical trials, garlic’s most common side effects are body odour, bad breath, and garlic allergy.

Garlic allergy symptoms

Garlic allergy symptoms are often experienced within a few minutes of contact with garlic, but for others it may take a few hours before they can witness them. The most common symptoms are those that affect the skin, like rashes and asthma. These garlic allergy symptoms can show up even after touching or inhaling garlic. Symptoms of garlic allergy can either be mild or severe depending on the individual’s reaction. Symptoms include:

  • Skin inflammation.
  • A tingling sensation of the lips, mouth, or tongue.
  • Nasal congestion or runny nose.
  • Itchy nose.
  • Sneezing.
  • Itchy or watery eyes.
  • Shortness of breath or wheezing.
  • Nausea and vomiting.
  • Stomach cramps.
  • Hives, itching, or redness of the skin.
  • Swelling around the mouth, tongue, face, or throat.
  • Anaphylaxis.
  • Fast heartbeat.
  • Stomach pain.
  • Diarrhoea.
  • Dizziness or fainting.

Differentiating garlic allergy and garlic intolerance

Garlic allergy, as seen above, can be very dangerous because when symptoms like anaphylaxis show up, this tends to be life-threatening and needs immediate medical help. On the other hand, garlic intolerance is not as serious and can’t be life-threatening. The severity of garlic intolerance increases with the amount of garlic you consume. Food allergies are often confused with food intolerance, which also applies to garlic. It is wise to note that garlic intolerance symptoms often dwell in the gastrointestinal tract. In contrast, garlic allergy symptoms often include skin reactions, like contact dermatitis.

While garlic allergy results from the immune system mistaking garlic for a dangerous substance, food intolerance is due to the body being sensitive to the proteins present in garlic or the body lacking enzymes required to digest proteins in garlic. When you suffer from garlic allergy, it doesn’t matter how much you consume; you will still experience the symptoms. However, the amount of garlic you often consume matters in garlic intolerance. Most people have some tolerance for the food they are intolerant to. So, if you consume too much of that food or ingredient, that’s when things go wrong, and you experience severe symptoms.

The symptoms of garlic allergy happen within a few minutes to two hours. In garlic intolerance, it may take up to three days to witness the symptoms, which makes it hard to pinpoint the cause to a specific food item or ingredient. Food intolerance symptoms take a long time to show up because food must reach the colon first before you can see or witness any signs.

Intolerance to garlic

Our Complete Intolerance Test Box.

Garlic intolerance is caused by the lack of certain digestive enzymes that are supposed to help break down or process garlic. Intolerance to garlic can also be caused by other conditions such as irritable bowel syndrome, celiac disease, or even stress. Intolerance to garlic and other foods is often a result of a myriad of issues, and that’s why we advise you to talk to your doctor to check for underlying problems before you can take our Intolerance Test kit.

When a certain food isn’t broken down in the small intestines, it gets pushed to the colon. Here, it ferments and forms gas, and that’s when you start hearing the stomach rumble, and you get gassiness and stomach cramps. Having garlic intolerance can be very uncomfortable because of these symptoms. It is common for these symptoms to subside and finally come to a halt once you’ve passed on the food, which in this case is garlic.

Garlic intolerance symptoms

Symptoms of garlic intolerance dwell in the digestive tract but are not limited to there. The symptoms of garlic intolerance often vary from one individual to the next based on your level of intolerance for that specific food item. Symptoms of garlic intolerance include:

  • Bloating.
  • Gassiness.
  • Stomach ache or cramps.
  • Diarrhoea.
  • Coughing.
  • Headaches.
  • Nausea.
  • A runny nose.

Garlic intolerance remedy

The best way to remedy garlic intolerance is by avoiding consuming garlic. The same applies to garlic allergy. It is possible to find substitutes for this flavour and add it to your meals to prevent experiencing symptoms after eating food loaded with garlic. You can also talk to your doctor (once you’ve proved you have garlic intolerance by taking an Intolerance Test). Under their supervision, they can help you go on a garlic-free diet for a couple of weeks, and after you’re finally feeling well, they’ll help you reintroduce it slowly. This method can help you know the amount of garlic you can use without experiencing a reaction. However, this method is not effective for garlic allergies, where the only remedy is to completely cut it out from your meals.

You may also notice that when you have a garlic allergy or garlic intolerance, you will also suffer from reactions when you consume foods from the same family as garlic. These include:

  • Onions.
  • Chives.
  • Leeks.
  • Shallots.

Garlic is part of the allium family, meaning you may be allergic or intolerant to the above foods. That’s because the proteins or allergens in these foods are similar to each other, and if you’re allergic, your immune system will react to them in the same way. This is known as cross-reactivity. You will also need to be careful about what you’re eating by asking for the ingredients or checking the ingredients list when food shopping. You’ll find that most soups, pre-made marinades, and mixed spices contain garlic, and you’ll need to keep away from these. An allergy to garlic means that you will always have to be careful to avoid any contact you may have with this spice. Sometimes people with garlic allergy can also experience cross-reactivity with pollen allergies like birch pollen {2}.

Testing for garlic allergy and garlic intolerance

If you suspect you may suffer from either garlic allergy or intolerance, you need to talk to your doctor about your history and symptoms. Doing so will help the doctor determine what issue you may be having and whether there could be underlying diseases. If there aren’t any, you can take an Intolerance Test or an Allergy Test. You can pick these depending on which symptoms you have based on what’s listed above, or read more on our page dedicated to allergies vs intolerances. But if you’re still unsure, you can take an Allergy and Intolerance Test to check for both.

These home-lab test kits are great at helping you determine what could be causing the symptoms. It could be a garlic allergy, intolerance, or other foods you consume regularly. These tests check for common allergens to help you determine what is the cause of your symptoms. You can order your preferred test kit online, have it delivered within three days, and once you’ve collected your sample, send it back to the lab for testing, upon which you’ll receive your test result within a week. Find out more about your body and health without even leaving your home!


  1. Almogren, A., Shakoor, Z., & Adam, M. H. (2013). Garlic and onion sensitization among Saudi patients screened for food allergy: a hospital based study. African Health Sciences, 13(3), 689-693.
  2. Asero, R., Mistrello, G., Roncarolo, D., Antoniottib, P. L., & Falagiani, P. (1998). A case of garlic allergy. Journal of Allergy and Clinical Immunology, 101(3), 427-428.