Thermographic Quantification of Skin Prick Test Responses in Children: The Caloric Allergy Index

Background: Skin prick tests confirm Type-1 hypersensitivity. Due to human dependence, however, its application, measurement, and interpretation might reduce its diagnostic value. Medical thermography can provide non-invasive, objective and quantitative data in allergy tests.

Methods: We established the caloric allergy index(CAI) to quantify skin warming induced by allergens in comparison to positive(histamine) and negative(saline) controls. Thermal images were obtained using a mobile thermal camera during skin prick tests on 63 pediatric patients.

Results: Cohen's Kappa scores ranged from 0.432 to 0.838, indicating consistent agreement between CAI values and conventional wheal measurements. Agreement levels vary among allergen mixes, with Grass Mix(κ=0.838) and C.dactylis(κ=0.833) showing almost perfect agreement. D.pteronyssinus(κ=0.753) and D.farinae(κ=0.672) also exhibit substantial agreement. However, Tree Mix(κ=0.432), Cat(κ=0.488) and Dog epithelium(κ = 0.498) demonstrate moderate agreement. All positive reactions continued to warm during the test, whereas negative reactions did not show significant warming. The discernible temperature contrast between positive and negative reactions initiates within early phases, typically starting in 2-5 minutes, prior to the test termination at 15.minute.

Conclusion: This research establishes the diagnostic criterion for thermal analysis, which may be implemented in the routine assessment of skin prick tests. Medical thermography offers precise and quantitative data in allergy skin prick tests. Thermography in allergy can provide further insights into allergic inflammation and contribute to the diagnostic processes.
Key Words: Allergy, child, new diagnostic method, thermography, skin prick test, pediatrics, hypersensitivity, digital health, mobile health, diagnostics