Role of specific IgE and skin-prick testing in predicting food challenge results to baked egg

• Published in: Allergy and asthma proceedings Vol. 33; no. 3; pp. 275 - 281
• Main Authors: Cortot, Catherine F., Sheehan, William J., Permaul, Perdita, Friedlander, James L., Baxi, Sachin N., Gaffin, Jonathan M., Dioun, Anahita F., Hoffman, Elaine B., Schneider, Lynda C., Phipatanakul, Wanda
• Format: Journal Article
• Language: English
• Published: United States OceanSide Publications, Inc 01.05.2012; OceanSide Publications
• Subjects: Adolescent; Anaphylaxis; Baked Egg Challenge; Child; Child, Preschool; Egg Allergy; Egg Hypersensitivity - diagnosis; Egg Hypersensitivity - immunology; Eggs - adverse effects; Female; Food Allergy; Food Challenge; Humans; IgE; Immunocap; Immunoglobulin E - immunology; Male; Ovomucoid; Rast; ROC Curve; Skin Prick Test; Skin Tests
• ISSN: 1088-5412; 1539-6304
• DOI: 10.2500/aap.2012.33.3544

Previous studies suggest that children with egg allergy may be able to tolerate baked egg. Reliable predictors of a successful baked egg challenge are not well established. We examined egg white-specific IgE levels, skin-prick test (SPT) results, and age as predictors of baked egg oral food challenge (OFC) outcomes. We conducted a retrospective chart review of children, aged 2-18 years, receiving an egg white-specific IgE level, SPT, and OFC to baked egg from 2008 to 2010. Fifty-two oral baked egg challenges were conducted. Of the 52 challenges, 83% (n = 43) passed and 17% (n = 9) failed, including 2 having anaphylaxis. Median SPT wheal size was 12 mm (range, 0-35 mm) for passed challenges and 17 mm (range, 10-30 mm) for failed challenges (p = 0.091). The negative predictive value for passing the OFC was 100% (9 of 9) if SPT wheal size was <10 mm. Median egg white-specific IgE was 2.02 kU/L (range, <0.35-13.00 kU/L) for passed challenges and 1.52 kU/L (range, 0.51-6.10 kU/L) for failed challenges (p = 0.660). Receiver operating characteristic (ROC) curve analysis for SPT revealed an area under the curve (AUC) of 0.64. ROC curve analysis for egg white-specific IgE revealed an AUC of 0.63. There was no significant difference in age between patients who failed and those who passed (median = 8.8 years versus 7.0 years; p = 0.721). Based on our sample, SPT, egg white-specific IgE and age are not good predictors of passing a baked egg challenge. However, there was a trend for more predictability with SPT wheal size.