Title : Allergy testing efficacy in skin prick test vs specific IgE: A meta-analysis
Abstract:
Background: Skin prick test (SPT), also known as the puncture or scratch test, is considered the gold standard and is the most widely used test for allergy testing. IgE allergen testing does not rely on a gap in treatment and is not associated with possible adverse effects from the SPT itself. Though there have been smaller individual studies, there has not been a definitive consensus if the two are comparable across all common allergens. This study evaluates if IgE allergen testing is as effective at diagnosing allergies as the standard skin prick test.
Methods: We reviewed research studies published between 2018-2022 and indexed in EMBASE, Google Scholar, and PubMed databases to identify comparative studies investigating the efficacy of IgE testing in comparison to SPT. The articles were excluded if they did not investigate at least one of the commonly tested allergens. The outcomes were determined as positive tests by SPT and IgE allergen testing. Results are expressed as differences in odds ratio (OR), standard variance, and p-value. Statistical analysis was done using both fixed-effects and random-effects meta-analysis to compare the OR of subgroups and overall (Comprehensive Meta-Analysis Version 4 software; Biostat Inc., Englewood, NJ). Sensitivities, Specificities, Positive Predictive Value, and Negative Predicative Value were also evaluated for each allergen, as well as the combined studies.
Results: Seven studies were quantitatively assessed and included. Among 1,524 individuals, both diagnostic tests were done on each patient. The number of positive tests were determined for each test and each allergen. Repeating allergens among studies consisted of cat, cockroach, Dermatophagoides farina, Dermatophagoides pteronyssinus, and dog. The detection of allergies using SPT or IgE testing were similar across all allergens and studies (p=0.675). SPT was better for detection in cat and dog extracts (p=0.002 and 0.015 respectively) compared to IgE testing for cockroach and Dermatophagoides f (p=0.047 and 0.028 respectively) in a fixed-effects meta-analysis, but not in random-effects meta-analysis.
Conclusion: IgE allergen testing is as efficacious as SPT in detecting allergies.
Audience Take away:
• Will explain current clinical standards of diagnosing allergies.
• Will aid the audience in investing in different avenues of testing, more convenient to the patient.
• Can provide a stepping stone for further research subdivided in categories of allergies, such as inhalant versus contact
