The fresh fruit syndrome represents a cross-reaction between an allergen in raw fruit and birch pollen (Bet v1 and Bet v2).
The patient complains of itching of the lips and mouth with occasionally swelling of the lips.
The allergen is heat-labile and is destroyed by cooking the fruit
The reaction can occur with any fruit and it is not clear why most patients do not react to all fruit
The reaction can involve some vegetables particularly carrot and celery.
The reaction can also involve some nuts especially almond and hazelnut.
The sensitivity is considered not to be a threat but involvement of vegetables and nuts occurs in the more highly sensitized and at that point epipen usage is taught.
The reaction usually starts in individuals who have had a history of allergic rhinitis and conjunctivitis in the early spring (tree pollination season).
The patients usually begin to complain of itching of the mouth and tongue after eating a few types of raw fruit. Commonly the list of fruits creating the problem expands.