In Spain,allergensThe most common are those derived from eggs, fish and cow’s milk: between the three they account for almost the60% of all food allergies. However, the most dangerous to health, due to the reactions they cause, are nuts.
COW MILK.Its allergenic side is an almost exclusively child problem. Even though thecaseinis the most abundant protein in milk, sensitization occurs more frequently with beta-lactoglobulin and, to a lesser extent,alfalactoalbúmina. Heat does not destroy these two milk proteins, so boiling the milk is useless. The incidence of allergy to cow’s milk proteins varies according to different studies between 0.3% and 7.5% of the population. In some cases, rejection of these milk proteins is the first manifestation of an individual’s allergic predisposition. It has been observed that approximately40% of children sensitized to cow’s milk proteins develop allergies to other foods and 28% do so to environmental agents-pollens, mites, fungi, animal epithelia-. It is also frequently associated with atopic dermatitis. Genetic predisposition or atopy, being male and using artificial lactation instead of breastfeeding are the main predisposing factors to suffer from this allergy.
Egg.The proteins in the egg white are the problem. This explains why most children have their first symptoms when takingfrench omelette, especially if it is slightly curdled. When talking about children’s food allergy, we must pay attention to rejection as a guiding symptom.
Fish.Allergy caused byfish or shellfishit is more durable in its sensitization and can last for decades or a lifetime. Its own proteins, the histamine that is formed when it is broken down and theanisakis parasitecan cause allergic reactions. Specifically, this nematode, whose larvae live in the digestive tract of many marine species, from thehakeand thetunauntil theoctopusand theLobster, are responsible for serious crises in sensitive people. As seen in the chapter on fish, anisakis is introduced into humans by ingesting raw, salted, smoked, pickled, marinated or undercooked fish. No one is sure whether freezing the fish below minus 20 degrees for at least 72 hours and cooking it above 60 ° C is enough to kill the larvae, although if the freezing has been done offshore there is a greater chance of so be it. If only digestive symptoms appear due to parasitization, we are facing anisakiasis, and if skin manifestations or general symptoms develop, it is an allergic reaction. Currently, most researchers consider that for there to be an allergy it is essential that the worm has been in the digestive tract of the affected person. TheanisakiasisIt is frequent especially in societies such as Japan, where the ingestion ofRaw FishIt is very frequent. In our environment, the usual form of exposure is through the consumption of pickled anchovies. In addition, it must be taken into account that people with a fish allergy may have reactions after eating other foods, such asanimal meats-pig, chicken, rabbit- fed with fish meal.
Nuts.The main danger comes from the fact that on many occasions we are faced with hidden allergens and that they are responsible for most of theanaphylactic reactionsfatal or near fatal. In most children, the allergy to milk and egg is overcome with the passage of the years; sometimes like fish too, but with nuts it almost never goes away. In a 1990 study carried out in Barcelona, Amat and his collaborators refer to almonds (89%) as the most frequent sensitization, followed by peanuts (80%), hazelnuts (76%), walnuts (39%) and pine nuts (30 %) In our country. Thepeanutspecifically, it is a legume, so patients with allergies sometimes have symptoms with other legumes and vice versa. On the other hand, the appearance of allergy to various nuts is also frequent (approximately 2535% of those allergic to peanuts are also, for example, to walnuts, cashews or pistachios). Another issue that must be taken into account is the cross-reactivity that may exist in children allergic to it.latexwithchestnut, pine nut, sunflower seed and walnut, among other nuts.
