This was previously posted to my old blog, Itch, Swell, Ooze, Wheeze in May 2014. This is an updated version for 2020.
Allergy to potato is relatively uncommon but the symptoms can be quite severe. The main protein is patatin (or sol t 1) which is thought to be the allergen which causes the majority of allergic reactions. There are several case studies available which show anaphylactic reactions to potato, especially in its raw form. In older research from the sixties potato allergy was referred to as a “housewives allergy”, as the raw potato would cause an eczema reaction on the skin, cause allergic rhinitis or bring on asthma attacks from peeling potatoes.
Potato is not one of the EUs top 14 allergens, so is harder to cater for those suffering from this allergy as it is not only a common food source in Western countries, but it is also added to processed food in various forms in things that you wouldn’t expect.
Look at labels
For those suffering with severe symptoms look for labels which state potato starch, potato flour, dried or powdered potato and as an ingredient in alcohol (like vodka). They will not be labelled as an allergen on packaging, so make sure you check very carefully if you suffer from a potato allergy.
Other Linked Allergies
Potato is part of the Nightshade family and has similar proteins in common with other members of this family such as tomatoes, aubergines (egg plant) and peppers. With the severest form of the allergy a person may experience allergic responses to other vegetables in the Nightshade family.
With some food proteins, like those found in egg, cooking can sometimes break down the proteins and cause either less of a reaction or none at all, these proteins are called heat labile.
The main potato protein, patatin (sol t 1) is heat labile and may be less effective in causing an allergic reaction when cooked. Unfortunately, other proteins found in potato (sol t 2, sol t 3 and sol t4) are thermostabile – which means they are not broken down by normal cooking temperatures, so may still cause allergic reactions in different forms.
Roasting, boiling, baking and mashing potatoes may make no difference to some people suffering with a potato allergy and then for others a certain way of preparing the vegetable may ease symptoms.
Different varieties of potato will have different levels of different proteins in, so depending on which protein you are reacting to there may be some types of potato that you would be able to tolerate, it may be a case of trial and error as to which you can eat. Sweet potato is a very distant relative of the potato and is not a member of the Nightshade family, so should be OK to eat as an alternative in most cases as it does not contain the problem protein patatin.
Birch Pollen and Latex Links
Potato allergy has been linked to birch pollen allergy and latex due to similar protein shapes. You may want to be careful with bandages and condoms as this is a common allergy which can cause swelling at the point of contact or in severe cases anaphylaxis.
Birch pollen in the United Kingdom is generally high between March and June. Anti-histamines can reduce the symptoms of hayfever.
This is a blog and should not be used for advice on diagnosis or treatments. If you think you may have a food allergy please contact your GP in the first instance to discuss treatment options.
References and Further Reading
Anaphylaxis to hidden potato allergens in a peach and egg allergic boy, 2017