Allergy to Potatoes

Image courtesy of Buzz Hoffman/Flickr.com

Buzz Hoffman/Flickr.com

Recently we received a question about  oral allergy syndrome cross-reactions that cause an allergy to potatoes. Before getting started remember we are an informational site only and are never to replace the relationship with you and your doctor (read more about our medical disclaimer here).

The potato, domesticated between 10,000 to 7,000 years ago, has been a major food source among diverse cultures and nations for centuries. Today potatoes are the leading vegetable crop in the United States and the fourth-largest crop in the world. In the United States over 50% of potato sales are from packaged French-fries, chips, dehydrated forms, and various other products. Since potatoes are such a staple ingredient in the human diet having an allergy to potatoes can be difficult to cope with and lead to much frustration. Fortunately having an allergy to potatoes is very rare and in many cases is caused by oral allergy syndrome.

Oral allergy syndrome and potatoes

Oral allergy syndrome is a type of food allergy that causes an itching, allergic reaction to the lips, mouth, tongue, and throat when eating uncooked fruits, vegetables, and nuts. (You can read more about oral allergy syndrome here.) Oral allergy syndrome symptoms are different with potatoes because most symptoms will happen when coming in contact with uncooked potatoes by peeling and/or handling them rather than just eating them. Uncooked potatoes can produce the hallmark oral allergy syndrome symptoms (read more here) but the most common symptoms are:

  • Contact urticaria: This is another term for “hives” which is a raised, burning, and/or itching rash-like reaction at the site where you touched or came in-contact with the uncooked potato. Additional symptoms of contact urticaria include swelling (at the site of contact or throughout the body including the face, ears, hands, and feet), a generalized whole-body reaction, and/or anaphylaxis.
  • Itching hands
  • Allergic rhinitis or hay fever symptoms during peeling
  • and/or wheezing during peeling

Oral Allergy Syndrome Cross-Reactions with Potatoes

If you have searched the internet about oral allergy syndrome and an allergy to potatoes you will quickly see some conflicting information. On some websites it says the cross-reaction is from tree pollen, another says grass pollen, and another says latex. Quickly this can become confusing and leave you wondering…which is it? Is an allergy to potatoes caused by tree pollen, grass pollen, or latex? The short answer is potentially all of them. In 1977 research showed a cross-reaction between birch pollen (tree pollen) and uncooked potatoes and in 1983 further research showed that there was also a cross-reaction between grass pollen and uncooked potatoes. Complicating things further, research also shows a cross-reaction with latex as well. Why?

There is no definitive information stating why potatoes can react to birch pollen, grass pollen, and latex but it may have something to do with the approximate 6 major allergens found in potatoes. Two of these known allergens are profilin and patatin and are known causes of oral allergy syndrome cross-reactions. Profilin is especially believed to be a cause of cross-reactions with tree pollens while patatin is believed to be a potential cause of the latex cross-reaction.

Something else to consider when determining the cause of an allergy to potatoes is a potential cross-reaction of foods within the same family.

Cross-reaction between foods

Potatoes are a tuberous crop from the perennial plant known as Solanum tuberosum in the Solanaceae family also known as the Nightshade family. The Nightshade family includes over 2,500 species that are used in medications and foods worldwide. Some of the notable members of this family are:

  • Potatoes (including russets, reds, whites, yukons or yellows, and purples. Does not include sweet potatoes.)
  • Eggplants
  • Tomatoes
  • Peppers: most notably red, yellow, and green bell peppers and chili peppers (such as cayenne, jalapenos, tabasco, and Thai peppers).
  • Tobacco
  • Deadly nightshade

It is possible that the oral allergy syndrome reactions you are experiencing with potatoes may be also caused by a cross-reaction within this family especially when dealing with tomatoes and eggplants.

How to find out the cause of an allergy to potatoes?

If you are having any symptoms when dealing with uncooked potatoes it is most likely you are experiencing oral allergy syndrome symptoms rather than a true allergy. To get properly diagnosed of which pollen or food cross-reaction is causing your symptoms you would need to see an allergist for skin testing.

Further Reading:

References

Disclaimer: The information contained in this site is for educational purposes only, and should not be used as a substitute for a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition. Click here to read the full disclaimer.
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