This was previously called Oral Allergy Syndrome (OAS) and the term was coined to define the symptoms. It has now been termed Pollen Food Allergy Syndrome (PFAS) more definitively as it mostly affects people who already suffer from pollen allergies and seasonal rhinitis and this is due to cross reactivity.
What is Cross Reactivity?
In terms of allergy, cross reactivity means that the body is mistaking the shape of a protein that it is already sensitive to (a plant pollen) to a similarly shaped protein in certain fruits, vegetables, spices, herbs, and nuts.
The symptoms of PFAS are like those of food allergies, swelling and/or itching of the mouth, lips, tongue and/or face after eating raw fruit, vegetables, nuts and/or spices.
It very rarely leads to anaphylaxis and it is less often associated with the other symptoms of food allergies, such as wheezing, hives, vomiting or digestive problems.
The symptoms are usually more short-lived than the symptoms of food allergy and ease quickly with antihistamines.
Onset of PFAS
Age of onset for Pollen-Food Allergy Syndrome seems to be in adulthood, with people having to experience hayfever symptoms before experiencing PFAS. There has been an increase in the number of children with PFAS as children have started to experience hayfever at an increasingly young age.
Which foods cause symptoms?
These have been grouped by which pollen was the initial trigger.
|Pollen||Fruit||Vegetables & Herbs||Nuts|
|Alder||Apples, cherries, peaches, pears||Parsley, celery||Almonds, hazelnuts|
|Birch||Kiwi, apples, pears, plums, peaches, nectarines, apricots, cherries, tomatoes||Celery, carrots, potatoes, parsnips, green peppers, dill, cumin, peas, coriander(cilantro), fennel||Hazelnuts, walnuts, almonds, peanuts, lentils, beans|
|Grass||Melon, watermelon, oranges, tomatoes||Potatoes||Peanuts|
|Mugwort (Artemisia)||Apples||Celery, carrots, dill, parsley, fennel, coriander (cilantro), cumin||Sunflower seeds|
|Ragweed (Ambrosia)||Watermelon, bananas||Courgette (zucchini), cucumbers, squash|
If you think that you are affected by Pollen Food Allergy Syndrome you should keep a food diary and make an appointment to see your GP. They should be able to diagnose you on symptoms alone.
A skin prick test may be undertaken by some health professionals, but the results with fruit and vegetables are not currently standardised.
- Taking antihistamines to alleviate symptoms
- Avoidance of foods causing symptoms
- Cooking/heating/freezing offending food
- Eating fresh or partially unripe fruit
- Peeling fruit/vegetables
- Eating the food outside of pollen season may give reduced symptoms
There are many anecdotal tales of pesticides on fruit and vegetables triggering the onset of PFAS, but there is currently no evidence to support this theory. You can supposedly eat organic or homegrown pesticide free variety of the food which causes symptoms, and this can allow you to eat more before experiencing symptoms. This is more likely due to organic fruit being more fresh and fresher fruit is thought to cause less symptoms.
This is a blog and should not be used for advice on diagnosis or treatments.
If you think you may have a food allergy, please contact your GP in the first instance to discuss treatment options.