Atopy patch test in the diagnosis of food allergy in children with gastrointestinal symptoms

Abstract

Purpose: To evaluate the diagnostic accuracy of the atopy patch test (APT) in detection of delayed-type sensitization to different food allergens, in children with digestive symptoms and with/or without cow's milk allergy.

Material and methods: 28 children suspected of food allergy-related gastrointestinal symptoms were underwent diagnostic procedures as skin prick test (SPT), specific immunoglobulin E (sIgE), APT, oral food challenge and then divided into two groups according to the results of oral food challenge: A - 17 children with cow's milk allergy, B - 11 children without cow's milk allergy. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of APT were calculated.

Results: A positive challenge response to milk was found in 60,7% of examined children. No statistical difference in the prevalence of positive SPT and sIgE to milk has been found between the groups. The prevalence of positive APT to other food allergens was significantly higher in children with allergy to milk (p<0,005). No statistical difference of positive APT to other food allergens has been found in children with/or without cow's milk allergy. APT sensitivity and specificity in children with cow's milk allergy obtained on 77%/73%; where PPV obtained on 71%.

Conclusions: High sensitivity and specificity of APT confirm its accuracy in diagnostics of delayed-type reactions in children with gastrointestinal symptoms. Combined atopy patch test and oral food challenge is essential for avoidance of unnecessary elimination diet. Delayed-type sensitization to other food allergens is common in children with cow's milk allergy.