Dairy Products and Allergies
Milk and dairy products present allergens that develop one of the most common food allergies observed in children: cow milk protein allergy (CMA). Incidence of allergy to cow-milk protein falls between 2% and 7.5% worldwide (Caffarelli et al., 2010; Fiocchi et al., 2010; Vandenplas et al., 2007). It can be characterized as an immunologic-medi- ated adverse reaction to cow milk protein and it can be developed in the neonatal period or during the first years of life. CMA tends normally to remit during childhood, and is quite uncommon in adults (Fiocchi et al., 2010). The immediate reaction symptoms include anaphylaxis, cutaneous reactions with urticaria and edema, respiratory episodes, and gastrointestinal distress, including vomiting, diarrhea, and bloody stools (Fiocchi et al., 2010; Solinas et al., 2010). Similarly, the late-onset phenomenon is also characterized by cutaneous, respiratory, and gastrointestinal symptoms, including disorders like atopic dermatitis, milk-induced pulmonary disease, chronic diarrhea, and gastroesophageal reflux disease. These aftereffects can happen 1 hour to several days after the ingestion of cow milk. Most frequently, these allergies are due to whey proteins, mainly p-lactoglobulin, but can also be promoted by caseins (Caffarelli et al., 2010; Fiocchi et al., 2010; Vandenplas et al., 2007). In adulthood, rare cow milk allergy cases can be found and clinical research has shown that symptoms are quite severe, even when compared with children, including respiratory and cardiovascular impairments, as well as some frequency of anaphylactic shock (Lam et al., 2008). Because CMA affects mainly children, including the neonatal period, improper growth is a direct consequence and management guidelines are quite frequently addressed to ensure that children adequately develop. In breast-fed infants, mothers are commonly advised to avoid all cow milk-derived products; whereas in formula-fed children, the alternative is to replace cow milk products with hydrolyzed or amino-acid options. Milk allergens are known to preserve their biologic activity even after boiling, pasteurization, ultra-high-temperature processing, and evaporation for the production of powdered infant formula (Fiocchi et al., 2010). Prevention of CMA largely relies on avoidance of milk and dairy products containing cow-milk proteins. Milk from some other species may also need to be avoided: milk allergens of various mammalian species cross-react, with high-sequence homology among cow-, sheep-, and goat-milk proteins. The recent guidelines issued by the World Allergy Organization state that goat, sheep, and buffalo milk should not be used as a substitute for children with cow-milk allergy as they can expose patients to severe reactions (Fiocchi et al., 2010). Camel milk can be considered a valid substitute for children more than two years old. Mare and donkey milks can be considered as valid cow-milk substitutes, in particular (but not exclusively) for children with delayed-onset CMA. Many commercially available milk replacements for children and adults exist. Rice milk, soy milk, oat milk, coconut milk, almond milk, or milk based on carob seeds are sometimes used as milk substitutes. The current standard of care for the management of milk-allergic patients, in general, remains avoidance of suspected allergens. However, according to recent studies, immunotherapy could be a promising new therapeutic approach.