Fruits, nuts, and vegetables are said to be one of the healthiest foods for people of all ages. But some people are allergic to particular fruits, nuts and even vegetables. Why is it so?
Oral allergy syndrome is a common condition in which an adverse reaction occurs a few minutes after the consumption of fruits in patients with pollen-induced SAR or seasonal allergic rhinoconjunctivitis, noted a 2019 study by the National Center for Biotechnology Information (NCBI).
This can cause the mouths and throats of people with the allergy to become itchy, or they may even experience symptoms like a scratchy throat, or swelling of the lips, mouth, tongue, and throat. “This happens in up to 50 to 75 per cent of adults allergic to birch tree pollen,” noted research from the American Academy of Allergy Asthma and Immunology. This reaction occurs “because the proteins found in some fruits and vegetables are very similar to those found in pollen (a fine powdery substance, typically yellow, which are essential for sexual reproduction of flowering plants and plants that produce cones, according to the University of Western Australia). These proteins can confuse the immune system and cause an allergic reaction or make existing symptoms worse, which is referred to as cross-reactivity. In the case of pollen and foods, the result of cross-reactivity is called oral allergy syndrome (OAS) also known as pollen fruit allergy syndrome (PFAS)”, it added.
According to Dr Praveen Khilnani, Madhukar Rainbow Hospital, Delhi, in case of ‘cross reactivity’ one should suspect pollen allergy, especially if the symptoms appear after consuming a raw fruit. According to the expert, apple, almonds, hazel nuts, kiwi, peach, celery, or cucumber can all trigger allergies but one usually comes to know when a “fruit causes itching“. “Skin testing may further confirm it. If it is indeed a pollen allergy, it can cause breathing issues with runny nose due to allergic rhinitis,” Dr Khilnani said.
Although not everyone with a pollen allergy experiences PFAS when eating the following foods, they are commonly associated with these allergens, noted American College of Allergy Asthma and Immunology (ACAAI).
Birch pollen: apple, almond, carrot, celery, cherry, hazelnut, kiwi, peach, pear, plum
Grass pollen: celery, melons, oranges, peaches, tomato
Ragweed pollen: banana, cucumber, melons, sunflower seeds, zucchini
So, what can be done?
According to ACAAI, people affected PFAS “can usually eat the same fruits or vegetables in cooked form because the proteins are distorted during the heating process, and the immune system no longer recognises the food”.
ACAAI further noted that if a food cannot be eaten in cooked form, like melons, one must choose to “avoid eating those foods” if they cause intolerable symptoms. If you experience significant throat discomfort or difficulty swallowing, or have systemic symptoms, reactions to cooked forms of the foods, or symptoms to high-risk foods such as peanut or tree nuts, your allergist may prescribe an epinephrine auto-injector, it added.
Taking the allergy treatment before this particular season begins and stop using any kind of you know windows or dusts or things which can aggravate these forms of allergy, added Dr Neha Rastogi Panda, senior consultant-infectious disease, Fortis Memorial Research Institute, Gurgaon.