Comparison of Cross Reactions Between Cow’s Milk and Other Mammals’ Milk Using Skin Prick Test and Atopy Patch Test in Children with Atopic Dermatitis and Cow’s Milk Allergy

Objective: The use of other mammals’ milk as an alternative treatment of cow’s milk allergy is controversial due to their similar protein structures. In the present study, we aimed to investigate cross reactions with sheep’s, goat, and camel’s milks using skin prick test and atopy patch test in children with cow’s milk allergy. Materials and Methods: Our study group was composed of patients with atopic dermatitis who were diagnosed with cow’s milk allergy in our former study where we investigated the sensitivity of different diagnostic tests commonly used to determine cow’s milk allergy. In all patients, cow’s milk, sheep’s milk, goat’s milk and camel’s milk were used for skin prick test and atopy patch test. The study data were analyzed with SPSS 20.0 for Windows. Results: Among the patients with cow’s milk allergy, 15 (63%) had early-onset and 9 (37%) late-onset reactions with provocation tests. Seven (70%) of 10 children who were found skin prick test positive with cow’s milk were shown to have a cross reaction against goat’s and sheep’s milk with skin prick test; 8 (88.8%) of 9 children who were found to be atopy patch test positive with cow’s milk had a cross reaction against goat’s milk, and 7 (66.6%) against sheep’s milk. No patient with cow’s milk allergy had a cross reaction with camel’s milk with either skin prick test or atopy patch test. Conclusion: Our study demonstrated that a cross reaction occurs at a quite high rate between cow’s milk, sheep’s milk and goat’s milk as revealed by both skin prick testing and atopy patch test, whereas there was no demonstrable cross reaction between cow’s milk and camel’s milk by either method.