Allergy to cow’s milk is common and is associated with allergen-specific IgE directed against both caseins and whey proteins. Worldwide sales of sports related protein products grew from $3.9 billion in 2007 to $7.6 billion in 2012 and are likely to reach $12.2 billion in 2017. Whey and soy are the dominant protein ingredients in sports food. A case of allergy to a whey protein supplement in the absence of clinical allergy to cow’s milk is reported here.
Case presentation
A 9-year-old male who had a prior history of food allergy (milk, egg, peanut, sesame) became skin test negative after age 5 and was able to consume these foods. He presented to the ER with facial swelling, generalized urticaria, pruritus, vomiting and tremor after he drank a whey protein drink following a soccer practice. Allergy skin test for foods (including milk) performed 4 weeks later were negative. Whey specific IgE level was positive at 0.93 kU/L. The patient avoided whey protein drinks but continued to drink milk with no symptoms. More than 1 year later, he presented to the emergency department with diffuse hives and angioedema after consuming a large amount of milk before and after a soccer practice. That reaction was likely related to the amount of whey, as he was able to consume regular amounts of milk since then.
Discussion
Whey proteins are normal constituents of milk that are separated from caseins during the production of cheese. Whey is a mixture of proteins which are commonly used in a variety of products (global whey protein market $5.4 billion 2014). Previously reported whey protein allergens include beta-lactoglobulin, alpha-lactalbumin, immunoglobulins, and albumin. Clinical allergy to whey protein has been previously reported in the context of cow’s milk allergy. It is more common in young children and tends to wane with age. The case illustrates that hypersensitivity to whey proteins may elicit allergic reactions when whey is consumed in concentrated form despite the lack of clinical cow’s milk allergy.
Conclusion
Whey protein powder allergy can occur in the absence of cow’s milk allergy. Considering the increase in protein sport drink consumption, clinicians should be aware of that occurrence. Analysis of the clinical presentation and the relevance of the available sIgE whey protein components ( Alpha-lactalbumin (f76) IgE, Beta-lactoglobulin (f77) IgE, Casein (f78) IgE) could be a focus of future research studies.
Allergy to cow’s milk is common and is associated with allergen-specific IgE directed against both caseins and whey proteins. Worldwide sales of sports related protein products grew from $3.9 billion in 2007 to $7.6 billion in 2012 and are likely to reach $12.2 billion in 2017. Whey and soy are the dominant protein ingredients in sports food. A case of allergy to a whey protein supplement in the absence of clinical allergy to cow’s milk is reported here.