Hen’s egg white hypersensitivity among a group of Egyptian atopic children

Background: Egg allergy is potentially life-threatening. The prevalence of egg allergy in Egypt is still unclear. This study is to evaluate the frequency of egg hypersensitivity in a group of Egyptian atopic children. Methods: Eighty allergic children were enrolled, each is subjected to clinical evaluation, skin prick testing (SPT) using a commercial egg white extract, and serum egg white specific IgE (SpIgE) estimation. Six patients with suspected egg allergy consent to perform open oral egg challenge. Results: Twenty-eight patients had history of exacerbation of their allergic diseases upon exposure to egg white, of these patients, 8 had negative SPT and serum egg white SpIgE. SPT was positive in 25 (31.2%) patients, of these patients, 3 (4%) were +3, 22 (28%) were +2, of whom 5 patients tolerate eggs without adverse effects. Serum egg white SpIgE was positive in 19 (24%) patients with a mean of 0.81 IU/ml (range: 0.35-4.52 IU/ML). Egg white allergy based on positive history, positive SPT and/or egg white SpIgE was detected in 23 (28.8%) patients. Open oral egg challenge was positive in one patient with positive history but negative tests giving an overall frequency of egg allergy of 30 % (n=24).While egg white SpIgE did not correlate with the ages, positive SPT was significantly more frequent among younger patients (t= 1.7, p=0.02). Egg sensitization and allergy did not affect the severity of asthma (p 0.05). Conclusion: Although positive SPT/ serum specific IgE to eggs are good tools for diagnosis, oral food challenge remains the gold standard in suspected cases. Further wide-scale studies are needed to outline the real prevalence of egg allergy in Egypt.