Allergy to Lipid Transfer Proteins (LTP Syndrome)

Lipid Transfer Proteins (LTPs) are found in plants and foods that contain plants. Lipid Transfer Protein Syndrome is an allergy affecting people who have become sensitised to LTPs . They may thus react to vegetables, fruits, nuts or cereals.  It is not known how many people have this allergy. The condition is more common in adults and is thought to be quite rare in children.


In many cases a reaction only occurs if there is an additional co-factor such as exercise, stress, drinking alcohol or having taken an NSAID (aspirin, ibuprofen or similar) within the last few hours.

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Symptoms of LTP allergy

  • Reactions to Lipid Transfer Proteins can occur after eating raw or cooked food. They usually start within 30 minutes of eating and can include tingling and swelling of the lips, mouth, face and eyes, hives (nettle rash), stomach ache, nausea, vomiting and, occasionally anaphylaxis (the term for a severe, potentially life-threatening allergic reaction).


  • Anaphylaxis can involve many different symptoms including difficulty breathing, a hoarse voice, chest tightness, a feeling of impending doom, faintness or collapse.  Please see our fact sheet on anaphylaxis for more information about this.


  • Whilst food allergy symptoms usually happen immediately after the food is eaten, they can sometimes be delayed by minutes or hours depending on whether a co-factor is involved.

Exercise and other co-factors

As stated above, people who are sensitised to Lipid Transfer Proteins may find they only have a reaction, or it is more severe, if the food involved has been eaten at the same time as, or within an hour or two of, exercise, drinking alcohol or taking a non-steroidal analgesic (such as aspirin and ibuprofen).


Stress may be another relevant co-factor.

Foods involved in LTP allergy

Each person with LTP allergy is an individual and only needs to avoid those foods which cause symptoms. Not all LTP-containing foods will cause a problem for them. Unfortunately the amount of LTP in foods may vary so it is hard to predict when a reaction may occur. Common foods involved in LTP allergy in the UK include hazelnuts, almonds, walnuts, apples, dried fruit, lettuce, tomatoes and foods containing concentrated forms of tomato such as pizza.

Most LTPs are in the peel and pips of plant foods. The following foods are likely to contain higher levels of LTP allergen:
  • right_arrow_orange_icon Foods made using whole unpeeled fruits or vegetable.
  • right_arrow_orange_icon Concentrated, processed, preserved or fermented fruits, vegetables or cereals.
  • right_arrow_orange_icon Dried fruit peel.

Keeping safe with LTP allergy

  • See your GP

    The key message for people who know or believe they are allergic to a food is: See your GP as soon as possible. You may be referred to an allergy clinic.

  • Carry prescribed medication

    The uncertainty about which foods might cause a reaction can make management of LTP allergy through food avoidance difficult.  Therefore people with LTP allergy should always carry prescribed medication.  An inhaler should be carried if asthma is also a problem.

  • Adrenaline auto-injectors (AAIs)

    People who are at risk of severe reactions are usually prescribed adrenaline auto-injectors (AAIs), which must be carried at all times. Anaphylaxis requires immediate medical attention. Once adrenaline has been administered, an ambulance must be called as further treatment in hospital may be necessary.

    Please see our fact sheet on adrenaline for more information about this.

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