Let me start with a real-life situation. A mum comes to me with her daughter who is allergic (as previously established by tests) to tree pollen. And indeed, she recounts the nightmares of April that ruined their trip to the mountains. But why does little Susanna complain in autumn of a constant swelling of the mouth and a swollen throat? “And besides, doctor, she’s such a picky eater that she doesn’t even want a sweet pear, you have to force it down into her! And the medicines from the paediatrician only help for a while. I no longer know what to do?” The old Polish adage about pears in a willow tree means an unrealistic plan, a misguided intention, something impossible. But it helps to remember the explanation for this strange illness.
Birch, or perhaps not only…
A brief reminder that the pollen of spring trees contains multiple proteins. Yes, yes – PROTEINS, which form and sustain life in the organisms of all plants and animals. Some of this goes straight into the grains from which we have flour and from this flour, for example, white borscht. Every housewife knows this. It is a little more difficult to believe that the same proteins are used to build the seeds of an apple, a tomato, nuts, or poppy seeds. Some of my patients have accurately claimed that birch pollen allergy and apple allergy have SOMETHING in common. This something was detected by biochemists, recognised as a sterol-carrying protein in plants and registered in a group of 10 proteins associated with plant diseases (international name PR-10). The proteins found in pollen and fruit from this group, which are essential for plants, were then named with codes from the Latin names of the plant in question. Mal d – from Malus domestica apple tree, Bet v 1- from Betula verrucosa birch, etc. More than 70% of patients sensitised to birch pollen develop allergic cross-reactions to the main allergen found in apple fruit, the 17.5 kDa protein Mal d 1. Allergic reactions to this protein result from initial sensitisation to the main birch pollen allergen, Bet v 1. Immunological cross-reactivity with E antibodies specific for PR-10 after apple consumption can cause severe oral allergic syndromes [1].
Did you know that, dear internaut? Or you wise internaut? And little Susanna’s instinct knew THIS. So she would rather not eat it. And rightly so! The detection of cross-allergens helped to explain part of the mystery of many Susanna-avoiders. Forcing fruits and vegetables that are harmful to the child must result in strange swellings of the tongue, cheeks and throat, and an itchy palate. Despite the ailments described, I do not forbid anyone from eating raw fruit or vegetables. I only recommend looking for the cause with tests. Precisely among the foods “closely and distantly related” to the birch tree. Every allergologist knows the list.
Or maybe it’s an oral allergy?
In practice, a visit to the dentist should be made first to establish the diagnosis of the disease causing the oral symptoms and to rule out dangerous causes besides allergy. When the problem disappears – the game is over. However, if the swellings recur and there is some runny nose, sneezing or itchy skin – we choose an allergologist. Let him carry out the classic and native skin spot tests and – if indicated – patch tests when the tongue burns. Let him order a serum sIgE for the so-called components. After a previous elimination and ingestion test, let him indicate the diet. “Fruit disliking” children would rather not be naughty at all, but have a local oral disease. Before we believe that Susanna grimaces “because she is nervous” let’s establish where the swelling comes from. And it is worth finding new meaning in old proverbs because similar relationships apply not only to willow pollen and pear fruit.
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Contact: buczylko@centrum-alergologii.lodz.pl
translation: Julia Majsiak
