Evaluation of positive patch test reactions using optical coherence tomography: A pilot study

Abstract

Introduction Patch testing is the gold standard for evaluating allergic contact dermatitis (ACD), yet current interpretation methods are limited by their subjectivity and possible variability between observers. Optical coherence tomography (OCT) imaging enables noninvasive in vivo skin visualization and holds promise as an objective method of patch test interpretation. Objective To evaluate the micromorphological changes of patch test reactions and identify objective, quantitative OCT markers that correlate with clinically graded patch test reactions. Results A total of 25 patch test reactions (7 grade‐0, 4 grade‐1+, 14 grade‐2+) from 7 patients underwent OCT evaluation. Increased epidermal thickness and density was qualitatively observed in grade 1+ and grade 2+ allergic reactions while well‐demarcated, signal‐free cavities were observed in all grade 2+ reactions. Attenuation coefficients significantly increased across the three reaction grades (2.58 ± 0.092, 2.96 ± 0.121, 3.05 ± 0.065; P < 0.01). Cutaneous blood flow at 0.35 mm monotonically increased with reaction grade severity and blood measurements significantly differed across the three reaction grades (0.053 ± 0.011 mm/s, 0.078 ± 0.015 mm/s, and 0.121 ± 0.008 mm/s; P < 0.01). Conclusions and Relevance Attenuation coefficient and cutaneous blood flow at 0.35 mm correlate with clinically graded patch test reactions and hold promise as objective, quantitative markers. OCT may help dermatologists differentiate clinical scoring of allergic reactions in patch test and thereby improve their diagnostic accuracy and interpretation of patch test reactions.

Optical coherence tomography in diagnosis of inflammatory scalp disorders

“…5 Also, it holds promise as an objective method of interpreting and grading patch test reactions. 6 The aim of this study was to describe the structural and vascular D-OCT findings of inflammatory scalp disorders including scalp psoriasis, seborrhoeic dermatitis and contact dermatitis and to compare OCT findings with trichoscopy features.…”

Patch test reactions through the lens of dermoscopy: Further insights, particularly on weak allergic reactions

“…Some noninvasive tests have been applied in an attempt to improve diagnostic specificity, including reflectance confocal microscopy, [9][10][11][12] ultrasound, 13 and conventional 14 as well as high-definition optical coherence tomography. 15,16 So far, only one previous paper has reported the use of dermoscopy in the assessment of reactions to patch tests. 1 This is rather surprising, as the dermatoscope, unlike other diagnostic devices, is a universal tool, very familiar to dermatologists and available in almost any outpatient setting.…”

Dynamische OCT − was verraten uns die Gefäße?

“…Ring et al konnten mit der D-OCT eine Art Kapillaroskopie durchführen und fanden Megakapillaren in Y-Form statt eines regulären feinen Gefäßsystems in gesunden Nagelfalzen [1, 4,15]. Weiterhin können mit der D-OCT auch objektiv Reaktionen im Epikutantest bei allergischer Kontaktdermatitis beurteilt werden [16]. Neben der erhöhten Epidermisdicke und -dichte konnte eine Zunahme des Blutflusses mit steigendem Reaktionsgrad festgestellt werden [16].…”

“…Weiterhin können mit der D-OCT auch objektiv Reaktionen im Epikutantest bei allergischer Kontaktdermatitis beurteilt werden [16]. Neben der erhöhten Epidermisdicke und -dichte konnte eine Zunahme des Blutflusses mit steigendem Reaktionsgrad festgestellt werden [16]. Außerdem waren zwischen den 3 Reaktionsgraden deutliche Unterschiede in den Messungen des Blutflusses zu verzeichnen [16].…”

“…Neben der erhöhten Epidermisdicke und -dichte konnte eine Zunahme des Blutflusses mit steigendem Reaktionsgrad festgestellt werden [16]. Außerdem waren zwischen den 3 Reaktionsgraden deutliche Unterschiede in den Messungen des Blutflusses zu verzeichnen [16].…”