Is serum total IgE levels a good predictor of allergies in children?

To study the role of Serum Total IgE levels as a marker of allergy and to see its association with different host and environmental factors, its association with different systemic allergies and with the increased allergic systemic involvement.

A cross sectional comparative study was conducted at Liaquat National Hospital Paediatric Medicine Unit and Outpatient Clinic, from December 2007 to October 2008. Two hundred and fifty eight children in the age group 6 months to 12 years meeting the inclusion criteria, were enrolled for the study. Complete blood count and serum total IgE levels were done in all patients. Data was collected and tabulated. Chi-square was applied to test the association of serum Total IgE levels with different variables using SPSS and p-value of <0.05 was taken as statistically significant.

Out of 258 patients 166(64.37%) had raised serum total IgE levels (108 males and 92 females). Among host factors there was no significant association of serum total IgE levels with age, sex, height of the patient, positive family history of allergy or age at which symptoms developed (p =or> 0.05), though the correlation of serum total IgE levels was seen with weight of the patient (p < 0.049), early weaning (p < 0.01) and bottle feeding (p < 0.01) in children. Among environmental factors serum total IgE levels had a strong association with exposure to passive smoking (p < 0.01), pollen (p < 0.01), cold (p < 0.01), and pets (p < 0.01). Blood eosinophilia was another factor that had positive association with allergy and raised serum total IgE levels (p < 0.01). However association of serum IgE levels was not statistically significant for any systemic allergies, skin allergy (0.608), food allergy (p < 0.210), allergic sinusitis (p < 0.113), allergic rhinitis (p < 0.358), allergic conjunctivitis (p < 0.507) except for bronchial asthma (p =or<0.01) where serum total IgE levels was also associated with severity of bronchial asthma (p < 0.01). Interestingly there was no significant relationship of increased number of systemic allergies with serum IgE levels.

Serum total IgE level is a good predictor of allergy in children. It is influenced by early weaning, early bottle feeding, exposure to passive smoking, pollen, cold, and pets and is associated with blood eosinophilia. Also serum total IgE level is a strong predictor of allergy in asthmatic children.