Diagnostic Performance of Skin Prick Test and Specific Immunoglobulin E in Children Sensitized to Cat Allergen

Cat allergen sensitization is common in childhood; however, the relationship between immunological test results and clinical symptoms remains unclear. Skin prick testing (SPT) and serum cat-specific immunoglobulin E (cat-sIgE) are widely used diagnostic tools, but their optimal cut-off values according to symptom status have not been well defined. This study aimed to evaluate cat allergen sensitization in pediatric patients, assess the diagnostic performance of SPT and cat-sIgE, and determine optimal cut-off values according to symptom status following cat exposure.

This retrospective cross-sectional study included children aged 0-18 years with cat allergen sensitization who underwent both SPT and cat-sIgE testing between January 2023 and January 2025. Patients were classified as symptomatic or asymptomatic based on documented allergic symptoms following cat exposure. Demographic characteristics, environmental exposures, comorbid allergic diseases, laboratory findings, and aeroallergen co-sensitization were analyzed. Multivariable logistic regression was used to identify factors associated with symptomatic status following cat exposure, and receiver operating characteristic (ROC) curve analysis was performed to evaluate diagnostic performance.

A total of 428 children were included, of whom 211 (49.3%) were asymptomatic and 217 (50.7%) were symptomatic according to clinical history following cat exposure. Cat exposure-related symptoms were predominantly nasal, followed by ocular, respiratory, and cutaneous symptoms. In the multivariable model, asthma was associated with higher odds of symptomatic status, whereas pollen sensitization, prenatal cat exposure, and longer duration of cat ownership were inversely associated with symptomatic status. ROC analysis demonstrated high diagnostic accuracy for both SPT wheal size and cat-sIgE levels, with higher cut-off showing high specificity for symptomatic status following cat exposure.

SPT wheal size and cat-sIgE levels showed diagnostic value in pediatric cat allergen sensitization. Laboratory sensitization should be interpreted together with clinical history, and distinct cut-off values based on symptom status following cat exposure may improve diagnostic accuracy and clinical interpretation.