Sheep's Milk - abstract

The true prevalence of goat's milk and sheep's milk allergy is not known. However, because IgE sensitization to sheep and goat casein has been found to be as high as 93% to 98% in children with IgE-mediated cow's milk allergy, it is to be expected that children who are allergic to cow's milk are also allergic to sheep's and goat's milks. Several case reports indicate that IgE-mediated sensitization and allergic reactions to sheep's and goat's milks can occur in children and adults who are tolerant of and not significantly sensitized to cow's milk. Because such sensitization and reactions have occurred with certain types of cheese and there are hundreds of different types of cheese, it is helpful to know the animal from which the cheeses are derived. Feta cheese can be made from cow, ewe, or goat; pecorino and Roquefort from ewe; ricotta from cow or ewe; mozzarella from cow, ewe, or buffalo. Other less common sources of milk used in cheese production include camel, mare, reindeer, and yak.

Symptoms of goat's milk and sheep's milk allergy may vary in severity from mild urticaria or localized oral pruritis to severe anaphylactic reactions.

The diagnosis of goat's and sheep's milk allergy is based on a thorough history supported by positive skin prick tests and high levels of specific serum IgE to goat's and sheep’s milk allergens, especially casein, respectively. Because of both the high association with cow's milk allergy and the sometimes isolated occurrence of sheep's and goat's milk allergy, testing with cow's milk can be informative. Oral challenge procedures can be performed when acute anaphylactic reactions are not expected, when the diagnosis is in doubt, or to determine if tolerance is present or has developed.

This review presents data on prevalence, symptoms, cross-reacting allergens, and sources in tabular form.

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Contents
1 Prevalence of Sheep's Milk Allergy 2 Symptoms of Sheep's Milk Allergy 3 Diagnostic Features of Sheep's Milk Allergy 4 Composition of Sheep's Milk 5 Allergens of Sheep's Milk	6 Cross-Reactivities 7 Allergen Sources 8 Food Allergen Labeling 9 References