Objectives: To investigate whether the development of tolerance to cow's milk (CM) by aged 4 years can be predicted with a skin prick test (SPT) and measurements of total or specific immunoglobulin E (IgE) in the serum, taken at the time of diagnosis of cow's milk hypersensitivity (CMH).
Study design: Infants with immediate (n=95) or delayed (n=67) challenge reactions to CM were prospectively followed to aged 4 years. CMH status was assessed annually by CM challenges.
Results: By aged 2, 3, and 4 years, children with delayed reactions developed tolerance to CM faster than those with immediate reactions: 64%, 92%, and 96% versus 31%, 53%, and 63%, respectively. A wheal size of <5 mm in SPT correctly identified 83% of 124 infants who developed tolerance to CM by aged 4 years, and a wheal size of >or=5 mm in SPT correctly identified 71% of 39 infants with persistent CMH. Milk-specific IgE <2 kU/L correctly identified 82% of infants who developed tolerance to CM, and milk-specific IgE >or=2 kU/L correctly identified 71% of infants with persistent CMH.
Conclusion: SPT and milk-specific IgE in the serum are useful prognostic indicators of the development of tolerance to CM in infants with CMH.