When you sit down to have a plateful, the last thing you expect is to start itching after the meal. Even though absurd, some foods could cause itching. The main reason for this is allergies. Food allergies and intolerances can cause physical symptoms including hives, bloating, and itching. Itching can be caused by various issues, but you may have food allergies if you notice that you start to itch after a meal. Food allergies result from your body viewing proteins in certain foods as “harmful.” As a result, the body releases histamine causing reactions like itching.

There are certain typical foods known to cause itching. These foods are also common allergens.

 

Cow’s Milk Allergy

Milk allergy is more common in children. The allergy-causing symptoms like itching are caused by two main culprits, namely casein and whey. Other symptoms you may notice apart from itching include:

  • Digestive problems
  • Swelling of the lips, tongue, and throat
  • Itching and tingling around the mouth
  • Anaphylaxis

Most but not all children outgrow milk allergies. The only way to cure this is by avoiding milk and other milk products like cheese, yoghurt, butter, and ice cream. There are now many cow milk substitutes available in supermarkets which you can read about here.

 

Egg Allergy

Egg allergies result from reactions to proteins found in egg whites and egg yolks. Most children with egg allergies outgrow them in their teenage years. Other common egg allergy symptoms include;

  • Hives (causing red, itchy, and swollen skin)
  • Digestive problems (like diarrhoea, stomach pain, and vomiting)
  • Shortness of breath

People with eczema have reported that eating eggs results in an itchy skin condition. If you find that you’re allergic to chicken eggs, you might also be allergic to other birds’ eggs, and it’s wise to avoid all types of eggs.

 

Fish Allergy

Even though egg and milk allergies tend to develop in childhood, fish allergy often develops in adulthood. Around 40% of adults with fish allergies say they developed it when they were older.  Fish allergies occur when the proteins present in fish, like parvalbumins, cause allergic reactions. Other symptoms of fish allergy excluding itching include:

  • Diarrhoea
  • Headaches
  • Hives or skin rash
  • Stomach ache
  • Stuffy nose

It is possible to be allergic to one type of fish but not the other. Most of the time, one is advised to avoid all kinds of fish (and their products) because of cross-contamination.

 

Shellfish Allergy

The types of fish that fall under the shellfish category are the ones that have a shell-like exterior or a hard shell. These include shrimps, squids, lobsters, oysters, crabs, and scallops. The protein tropomyosin found in shellfish is what causes allergic reactions. Depending on the severity of the allergy, individuals could experience mild reactions or in the worse case life-threatening symptoms. Mild symptoms include;

  • Nausea
  • Wheezing
  • Hives
  • Swelling in the face

The more severe symptoms of shellfish allergies include;

  • Anaphylaxis
  • Low blood pressure

Anaphylaxis can be fatal, and if one experiences it, they should get 911 to help immediately. Always carry an EpiPen with you if you have a history of anaphylaxis. When it comes to a shellfish allergy, you can be allergic to one type of fish but not others. However, it is important to be prepared if you have experienced symptoms after eating one type of shellfish, as it is common that you will experience the same reaction with others.

 

Wheat Allergy

Wheat is a prevalent food allergy affecting 1% of children and adults {1}. Wheat allergy results from reactions to wheat proteins like globulin, gluten, albumin, and gliadin. Other symptoms of wheat allergy include;

  • Digestive distress
  • Respiratory problems

Some studies show that wheat allergies are more common in individuals with underlying conditions like seasonal allergies, eczema, and asthma {2}. The best way to avoid experiencing these symptoms is by avoiding any foods or condiments with wheat as an ingredient.

 

Soy Allergy

Soy allergies are common, affecting around 0.5% of the general population {3}. Soy allergies are caused by the body reacting to proteins found in soy products like edamame, baby formula, tempeh, miso, tofu, and soybeans. Symptoms of this allergy include:

  • Atopic dermatitis
  • Wheezing
  • Tingling of the mouth
  • Stomach pain

It is better to avoid all soy products if you find out that you have a soy allergy. But there are soy-based products like refined soy lecithin and soy oil that you can safely consume without causing allergy flare-ups {4}.

 

Peanut Allergy

These are the most common causes for severe allergic reactions like anaphylaxis which can be life-threatening, making peanuts the most dangerous type of allergy {5}. Peanut allergies can differ from person to person as there are varying peanut proteins that could cause symptoms.  Common peanut allergy symptoms include;

  • Swelling
  • Hives
  • Digestives issues
  • Shortness of breath
  • Runny nose

It is also possible to have a more severe reaction to peanuts if you have asthma. If you are allergic to peanuts you must avoid all foods that have peanuts as an ingredient.

 

Tree Nuts Allergy

Unlike peanuts, tree nuts like cashews, almonds, walnuts, pistachios, brazil nuts, pecans, pine nuts, and hazelnuts grow on trees. Like peanuts, tree nuts are also a common cause of anaphylaxis in those allergic to nuts. Many people who have peanut allergies also suffer from one or more tree nut allergies. The proteins in tree nuts that cause allergic reactions include legumin, oleosins, visilins, and 2S albumins.

Common tree nuts allergy symptoms include;

  • Swelling of the mouth
  • Tingling
  • Skin redness

Conditions like eczema, asthma, and hay fever are associated with severe allergic reactions to tree nuts. Most of the time, people with tree nut allergies aren’t allergic to all types of nuts but are advised to stay away from all of them due to cross-contamination that often occurs during food production {6}.

 

Less common foods that cause itching

There are foods (or ingredients) we consume daily and don’t know can cause itching. These include:

Balsam of Peru allergy

People sensitive to Balsam of Peru tend to have dermatitis when they consume tomatoes. Balsam of Peru comes from a tree grown in South America. It is among the most common allergens used in manufacturing fragrances, flavourings, and some medicines. People sensitive to Balsam of Peru may react to spices (like cinnamon, vanilla, cloves), soft drinks, tomatoes, citrus fruits (like lemons, limes, oranges, and grapefruits), and chocolates.

Nickel allergy

Some foods contain nickel and end up causing itching or dermatitis in people who are allergic. These foods include whole wheat, oatmeal, beans, peas, lentils, canned foods, peas, and soybeans.

Spices allergy

A spice allergy can be a great annoyance since spices are used in so many dishes. Common spices that can cause allergic reactions include; garlic, fenugreek, vanilla, cinnamon, coriander, and cloves. These can cause reactions on the skin when used topically (like cosmetic products) and when eaten.

 

Can allergy testing help with foods that cause itching?

Our Allergy Test Box Kit

If you experience itching after consuming a particular type of food, it might be due to allergies. To find out for sure which food item is causing uncomfortable symptoms, you can order an Allergy Test kit online that measures your IgE. This test checks your blood sample against 35 common food allergies, including the ones we’ve talked about above.

Once you’ve sent back your sample to the Test Your Intolerance Lab, you’ll get your results within a week. If you suffer from any food-related allergies, you’ll need to avoid those foods and talk to your doctor about healthy substitutes that will help you prevent you from having any deficiencies.

 

About the Author

Kate Young is a clinical bio scientist and embryologist in both clinical NHS hospitals and private laboratories in the UK and Japan. She graduated with a BSc in Human Biological Studies from Leicester University, moved to Japan in 2006, where she specialized in IVF and embryology.

The early years of her career included Lab supervisor at Nottingham City Hospital’s Sperm Bank and Product Research and Development Technician at Boots PLC in Nottingham, testing sunscreen SPF’s and non-irritant baby products before focusing her expertise in ART (Assisted Reproductive Technology) and Genetics, which became her passion. You can find more about Kate, Healthy Stuff Lab Manager, here.

 

References

  1. Patel, N., & Samant, H. (2021). Wheat allergy. StatPearls [https://www.ncbi.nlm.nih.gov/books/NBK536992/].
  2. Ricci, G., Andreozzi, L., Cipriani, F., Giannetti, A., Gallucci, M., & Caffarelli, C. (2019). Wheat Allergy in Children: A Comprehensive Update. Medicina (Kaunas, Lithuania), 55(7), 400. https://doi.org/10.3390/medicina55070400
  3. Katz, Y., Gutierrez-Castrellon, P., González, M. G., Rivas, R., Lee, B. W., & Alarcon, P. (2014). A comprehensive review of sensitization and allergy to soy-based products. Clinical reviews in allergy & immunology, 46(3), 272–281. https://doi.org/10.1007/s12016-013-8404-9
  4. Awazuhara, H., Kawai, H., Baba, M., Matsui, T., & Komiyama, A. (1998). Antigenicity of the proteins in soy lecithin and soy oil in soybean allergy. Clinical and experimental allergy: journal of the British Society for Allergy and Clinical Immunology, 28(12), 1559–1564. https://doi.org/10.1046/j.1365-2222.1998.00431.x
  5. Patel, R., & Koterba, A. P. (2021). Peanut Allergy. StatPearls [https://www.ncbi.nlm.nih.gov/books/NBK538526/].
  6. Weinberger, T., & Sicherer, S. (2018). Current perspectives on tree nut allergy: a review. Journal of asthma and allergy, 11, 41–51. https://doi.org/10.2147/JAA.S141636
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