Potato allergy
Potato allergy, including to raw potato proteins.
About potato allergy
Potato allergy is relatively rare but well recognised, and it can involve different proteins depending on whether the potato is raw or cooked. Reactions are usually IgE-mediated, with the immune system producing antibodies to potato proteins such as patatin. Some people react mainly when handling or peeling raw potato, while others react to the cooked vegetable; young children with other food allergies or eczema appear more prone to it.
Symptoms typically appear within minutes to two hours and can include an itchy or swollen mouth, hives, contact rash on the hands from raw potato, stomach upset, runny nose from cooking vapours and, less often, wheeze or anaphylaxis. Because potato is a member of the nightshade family, some people also report sensitivity to related foods, and there can be links with birch and grass pollen or with latex in certain individuals, though patterns vary considerably.
Diagnosis rests on the history alongside skin-prick testing (sometimes with fresh potato) or specific-IgE blood tests, and occasionally a supervised challenge, since cooked and raw forms may behave differently. Management means avoiding potato in the form that triggers symptoms and being alert to it in crisps, processed foods and starch. Mild reactions may need no more than avoidance, but throat swelling or breathing difficulty is a medical emergency requiring 999.
Common triggers
- Potato and products containing it
Symptoms
- Itching or tingling in the mouth
- Hives, itching or eczema
- Swelling of the lips, face, tongue or throat
- Stomach cramps, nausea, vomiting or diarrhoea
- Wheezing or trouble breathing
- In severe cases, anaphylaxis
Avoidance & management
- Read ingredient labels every time
- Ask about ingredients and cross-contamination when eating out
- Keep the food out of shared cooking areas
- Carry prescribed antihistamines or an adrenaline auto-injector
- Seek emergency help for any severe reaction
Sources & references
Allergy safety: what everyone should know
Mild-to-moderate reaction signs
- Itching, hives or a raised rash
- Swelling of lips, face or eyes
- Tingling mouth, sneezing, runny nose
- Stomach pain, nausea or vomiting
Anaphylaxis — call 999 (UK) or 112 (EU) immediately
- Difficult or noisy breathing, wheeze, persistent cough
- Swelling of the tongue or tightness in the throat
- Dizziness, collapse, pale and floppy (young children)
- Use an adrenaline auto-injector (e.g. EpiPen) at once if prescribed, then call an ambulance even if symptoms improve
Allergy or intolerance? A true allergy involves the immune system and can escalate quickly; an intolerance (e.g. lactose intolerance) is unpleasant but not life-threatening. The symptoms overlap, so self-diagnosis is unreliable.
Getting tested: home-testing kits based on IgG are not diagnostically valid. If you suspect an allergy, ask a GP for referral to an allergy clinic for skin-prick or specific-IgE testing and a supervised food challenge where appropriate.