Abstract
Background and objective Multiple-head skin prick test (SPT) devices are essential tools for percutaneous allergy testing; however, significant interdevice variability exists that may affect diagnostic accuracy, clinical performance, and interpretation. Intradevice variability, characterized by inconsistent responses across individual test heads, may lead to false-positive or false-negative results, potentially compromising allergen identification and treatment planning. This prospective study compared four FDA-cleared multiple-head SPT devices with respect to pain perception, histamine sensitivity, glycerin specificity, and intradevice variability to identify clinically meaningful performance differences. Methods Thirty healthy adults participated in this institutional review board-approved study (approval 33-098). Participants were tested with two 10-head devices (AllerTest-10 (MedScience Research Group, Inc., West Palm Beach, FL, USA; distributed by ALK-Abelló, Inc., Port Washington, NY, USA) and Skintestor OMNI (Greer Laboratories, Inc., Lenoir, NC, USA)) and two eight-head devices (AllerTest-8 (MedScience Research Group, Inc.; distributed by ALK-Abelló, Inc.) and Multi-Test II (Lincoln Diagnostics, Inc., Decatur, IL, USA)). Pain was assessed using a Visual Analog Scale (VAS; 0-10). Histamine (1 mg/mL) and glycerin controls were applied to volar forearm surfaces. Sensitivity was defined as a histamine wheal ≥3 mm, and specificity as a glycerin wheal <3 mm. Intradevice variability was expressed as the coefficient of variation (CV) across test heads. Results Pain scores were low across all devices (mean VAS, 0.92-1.77), with no statistically significant differences. Among the 10-head devices, AllerTest-10 demonstrated superior sensitivity (88% vs. 68%; P = 0.002) and significantly lower intradevice variability (median CV, 0.18 vs. 0.72; P = 0.00024) compared with Skintestor OMNI. Among the eight-head devices, AllerTest-8 showed higher sensitivity (96% vs. 88%; P = 0.026) than Multi-Test II. Both AllerTest devices achieved 100% specificity, whereas comparators achieved 97%-98%. AllerTest devices demonstrated consistently low CV values (0.18-0.19), indicating superior test-head uniformity. Conclusions All evaluated devices demonstrated acceptable patient comfort and clinical performance. However, AllerTest devices exhibited superior clinical performance, characterized by higher histamine sensitivity, perfect glycerin specificity, and markedly lower intradevice variability. These findings suggest that device selection may meaningfully affect diagnostic accuracy, with lower intradevice variability reducing the likelihood of physician misinterpretation and improving the reliability of allergen identification.