Baked egg food challenges - clinical utility of skin test to baked egg and ovomucoid in children with egg allergy.

Abstract

BACKGROUND:

Many children with IgE-mediated egg allergy can tolerate products containing extensively heated (baked) egg. Aside from food challenge, there are no tests which reliably predict tolerance to baked egg in egg-allergic individuals.

OBJECTIVES:

To determine if skin prick test (SPT) to baked egg (muffin) and ovomucoid can predict the outcome of baked egg challenges in egg allergic patients.

METHODS:

In this prospective study, children with a recent history of immediate allergic reactions to egg [and corroborative positive SPT or serum-specific IgE (ssIgE) to egg] or those with SPT/ssIgE > 95% PPV for egg allergy were invited to undergo an open standardized baked egg (muffin) challenge. SPT to egg white, ovomucoid, and fresh muffin were performed immediately prior to challenge.

RESULTS:

One hundred and forty-three egg allergic children underwent baked egg challenge and of these, 90 (63%) tolerated 1 g of egg protein in a baked muffin. Of the 53 positive challenges, eight (15%) had respiratory and/or cardiovascular symptoms. The median SPT diameters in positive challenges compared with negative challenges were baked muffin - 6.0 mm/4.0 mm and ovomucoid 7.5 mm/5.0 mm respectively. Receiver operating characteristic (ROC) curves were generated for SPT to baked egg and ovomucoid. The area under the curve was 0.68 for baked egg, and 0.67 for ovomucoid. A muffin SPT of < 2 mm had a negative predictive value of 88% and an ovomucoid SPT ≥ 11 mm had a positive predictive value of 100%.

CONCLUSIONS AND CLINICAL RELEVANCE:

A SPT of < 2 mm to muffin had a high negative predictive value to baked egg challenge. Ovomucoid SPT ≥ 11 mm was very likely to predict a reaction to baked egg. In these children, deferring the challenge would be appropriate.

• Authors: J W-L Tan, D E Campbell, P J Turner, A Kakakios, M Wong, S Mehr, P Joshi
• Journal: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology (Clin Exp Allergy) Vol. 43 Issue 10 Pg. 1189-95 (Oct 2013) ISSN: 1365-2222 [Electronic] England
• PMID: 24074337 (Publication Type: Journal Article)
• Copyright: © 2013 John Wiley & Sons Ltd.

Chemical References

• Allergens
• Ovomucin

Topics

• Allergens (administration & dosage, immunology)
• Child
• Child, Preschool
• Egg Hypersensitivity (diagnosis, immunology)
• Eggs (adverse effects)
• Female
• Humans
• Infant
• Male
• Ovomucin (immunology)
• Prognosis
• Prospective Studies
• ROC Curve
• Reproducibility of Results
• Risk Factors
• Skin Tests