The Role Of Skin Prick Testing And Specific IgE To Boiled Versus Unheated Cow Milk In Cow Milk Allergic Children

Abstract

The majority of cow milk(CM) allergic children can tolerate extensively heated milk. There is a commercially available IgE antibody measurement to boiled milk(BM) but the clinical significance is unknown. Children ages 2 to 18 with known CM allergy underwent skin prick testing(SPT) to CM extract and CM extract that was boiled at 95°-100°C for 5, 10, and 20min. IgE antibody to CM and BM were measured. Subjects were then challenged to BM. Nine subjects were recruited. Mean CMSPT wheal was 10.3mm(range 4-15mm) compared to BMSPT wheals of 10.7mm(range 3-20mm), 9.1mm(range 0-20mm), and 6.4mm(range 0-15mm) at 5, 10, and 20min, respectively. There was a trend toward significance comparing CMSPT and BMSPT at 20min(p=0.07). Mean CM specific IgE was 13.2 kU/L(range <0.35-43.9). Mean BM specific IgE was 12.5 kU/L(range <0.35-44.9). The Pearson correlation coefficient for the CM and BM IgE was 0.998(p<0.0001). Three subjects completed a BM challenge. One subject passed and CMSPT wheal was 8mm and BMSPT wheals at 5, 10, and 20min were 10mm, 5mm, and 3mm. The subject's specific IgE to both CM and BM was <0.35. Two subjects failed the OFC and mean CMSPT wheal was 12.5mm and BMSPT wheals at 5, 10, and 20min were 15mm, 10mm, and 9mm. The mean specific IgE to CM was 29.1 and BM was 28.8. The CM and BM specific IgE appear to be highly correlated such that the BM IgE may have questionable clinical utility in predicting BM tolerant children. SPT to BM at 20min may be clinically useful.