Thermo‐SPT: A new skin prick test evaluation framework based on low‐cost, portable smartphone thermography

Abstract

Background: Although the skin prick test (SPT) is a reliable procedure to confirm IgEdependent allergic sensitization in patients, the interpretation of the test is still performed manually, resulting in an error-prone procedure for the diagnosis of allergic diseases.Objective: To design and implement an innovative SPT evaluation framework using a low-cost, portable smartphone thermography, named Thermo-SPT, to significantly improve the accuracy and reliability of SPT outcomes.Methods: Thermographical images were captured every 60 s for a duration of 0 to 15 min using the FLIR One app, and then analysed with the FLIR Tool ® . The definition of 'Skin Sensitization Region' area was introduced to analyse the time-lapse thermal changes in skin reactions over several time periods during the SPT. The Allergic Sensitization Index (ASI) and Min-Max Scaler Index (MMS) formulae were also developed to optimize the identification of the peak allergic response time point through the thermal assessment (TA) of allergic rhinitis patients.Results: In these experimental trials, a statistically significant increase in temperature was detected from the fifth minute of TA for all tested aeroallergens (all p values < .001).An increase was observed in the number of false-positive cases, where patients with clinical symptoms not consistent with SPT were evaluated as positive on TA assessment, specifically for patients diagnosed with Phleum pratense and Dermatophagoides pteronyssinus. Our proposed technique, the MMS, has demonstrated improved accuracy in identifying P. pratense and D. pteronyssinus compared with other SPT evaluation metrics, specifically starting from the fifth minute. For patients diagnosed with Cat epithelium, although not statistically significant initially, an increasing trend was determined in the results at the 15 min (ΔT (T 15 − T 0 ), p = .07; ASI T15 , p < .001).

Novel diagnostics and therapeutic approaches for allergic diseases

“…This issue of Clinical & Experimental Allergy features the work of Goktas et al 4 The authors used an innovative digital approach and integrated infrared thermography (IRT) system with the standard SPT procedure to assess allergen‐induced skin reactions at multiple time points, thereby enhancing the capabilities of the SPT in this regard. Using infrared radiation as a method of monitoring skin surface temperature in the human body, IRT can be considered as a non‐invasive, contactless method.…”