Improved Allergy Wheal Detection for the Skin Prick Automated Test Device
Journal:
arXiv
Published Date:
Jun 6, 2025
Abstract
Background: The skin prick test (SPT) is the gold standard for diagnosing
sensitization to inhalant allergies. The Skin Prick Automated Test (SPAT)
device was designed for increased consistency in test results, and captures 32
images to be jointly used for allergy wheal detection and delineation, which
leads to a diagnosis.
Materials and Methods: Using SPAT data from $868$ patients with suspected
inhalant allergies, we designed an automated method to detect and delineate
wheals on these images. To this end, $10,416$ wheals were manually annotated by
drawing detailed polygons along the edges. The unique data-modality of the SPAT
device, with $32$ images taken under distinct lighting conditions, requires a
custom-made approach. Our proposed method consists of two parts: a neural
network component that segments the wheals on the pixel level, followed by an
algorithmic and interpretable approach for detecting and delineating the
wheals.
Results: We evaluate the performance of our method on a hold-out validation
set of $217$ patients. As a baseline we use a single conventionally lighted
image per SPT as input to our method.
Conclusion: Using the $32$ SPAT images under various lighting conditions
offers a considerably higher accuracy than a single image in conventional,
uniform light.
