The allergen associated with lemon allergy is called Cit l 1.
Cit l 1 is a Lipid Transfer Protein (LTP), these proteins are resistant to heat and are found in many types of plants. Patients suffering from a more severe allergy to cooked fruit may be sensitised to this group of proteins
Lemons also contain limonene, which is a component of the oils found in the peel of certain fruits. Limonene is a well known skin irritant - so may cause sufferers to react to the skin whilst being able to eat or drink the fruit.
You may be suffering from LTP Syndrome if you have reactions to various fruits, vegetables and nuts and your reactions continue to be severe after you have discarded the peel and have cooked the food.
Common foods involved in LTP allergy include kiwi, strawberries, sunflower seeds, walnut, apple, mulberry, banana, pea, apricot, cherry, plum, almond, peach pomegranate, raspberry, tomato, grape, celery, peanut, asparagus, cabbage, broccoli, chestnut, lemon, tangerine, orange, hazelnut, lettuce, lentils, lupin, green bean, pear, mustard, wheat and maize.
Lemon allergens have shown cross-reactivity with the major peach allergen Pru p 3.