Component-resolved diagnostics in Thai children with cow's milk and egg allergy.

BACKGROUND AND OBJECTIVE: Component-resolved diagnostics (CRD) have garnered a lot of attention in recent years in the diagnosis of food allergies. We aimed to investigate sensitization against cow's milk and egg white components, and to study the clinical usefulness of serum food-specific immunoglobulin E (sIgE) to cow's milk and egg white components in Thai children with cow's milk and egg allergies.

METHOD: Children with IgE-mediated cow's milk and/or egg allergy were enrolled. Clinical reactions were determined. Specific IgE against cow's milk, egg white, alpha-lactalbumin (ALA), beta-lactoglobulin (BLG), casein, ovomucoid, ovalbumin and conalbumin were measured.

RESULTS: Thirteen cow's milk allergic subjects and 32 egg allergic subjects were identified. The sensitization rate to BLG and casein was 91.7%, followed by ALA (66.7%) for cow's milk, and the sensitization rate to ovalbumin was 93.8%, followed by ovomucoid (81.3%) and conalbumin (37.5%) for egg. Patients in the urticaria group had a higher level of casein sIgE than the atopic dermatitis (AD) group but this difference was not significant (9.8 kUA/L vs. 0.9 kUA/L, p = 0.11). The level of ovomucoid sIgE was significantly higher in the non-AD group than in the AD group (3.8 kUA/L vs. 1.3 kUA/L, p = 0.048).

CONCLUSIONS: BLG and casein for cow's milk and ovomucoid and ovalbumin for egg were the common components causing sensitization in cow's milk and egg allergic patients. Among the patients with cow's milk allergy, the level of casein sIgE in the urticaria group tended to be higher than the AD group, and in egg allergic patients, the non-AD group had a significantly higher ovomucoid sIgE level compared with the AD group.