Allergy to potato is relatively uncommon, but it can be quite nasty. The main allergy causing protein is patatin (or sol t) which is thought to cause reactions. There are several case studies available which show anaphylactic reactions to potato, especially in its raw form and in older research from the sixties was referred to on occasion 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 a top 14 allergen (according to the Food Standards Agency), so is harder to cater for those suffering from this 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 out for 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 UK packaging, so make sure you check very carefully if you or your child suffer from a potato allergy.
Other Linked Allergies
Potato is part of the Nightshade family or Solanaceae, so has similar proteins in common with other members of this family such as tomatoes 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 in egg, sometimes cooking can break down the proteins and cause either less of a reaction or none at all. Unfortunately some of the proteins in potato are heat labile – 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 this type of allergy and then for others a certain way of preparing the vegetable may ease symptoms.
Typically different varieties of food have different levels of different proteins in, so depending on which protein you were 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 however 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 (though if you suffer from multiple food allergies this may not be a viable option either).
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 fairly common allergy which can cause swelling at the point of contact or in severe cases anaphylaxis.
A pollen allergy would cause symptoms of hayfever, there is a great website here which shows when which pollens are high and also which holiday destinations are best for pollen sufferers. Birch pollen in the United Kingdom is generally high between March and June. Anti-histamines can reduce the symptoms of hayfever.
If you think you suffer from any of these allergies you should seek medical advice from your GP, allergist or dietician
García, B. E., & Lizaso, M. T. (2011). Cross-reactivity syndromes in food allergy. J Investig Allergol Clin Immunol, 21(3), 162-70.