Diagnostic concordance of dermatopathology and PCR in differentiating eczema from psoriasis.

Cohort studyJournal of the European Academy of Dermatology and Venereology : JEADV· Jul 2026

Diagnostic concordance of dermatopathology and PCR in differentiating eczema from psoriasis.

Andrea Schmitt, Susanne Proksch, Ludwig Gutzweiler … Kristin Technau-Hafsi

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Inflammatory & ImmunodermatologyCohort studyDiagnosisQ1IF 3.1

Polymerase chain reaction testing differentiates psoriasis from eczema more sensitively than dermatopathology.

Diagnostic concordance of dermatopathology and PCR in differentiating eczema from psoriasis.

Andrea Schmitt … Kristin Technau-Hafsi

Journal of the European Academy of Dermatology and Venereology · Jul 2026

Background

Targeted treatments for non-communicable chronic inflammatory skin diseases like eczema and psoriasis offer significant potential for effective therapy.

Purpose

We aimed at assessing the diagnostic performance of both a manual (MC) and fully automated (PsorX-LabDisk) quantitative real-time polymerase chain reaction (real-time polymerase chain reaction) test based on the expression of NOS2 and CCL27 compared with conventional dermatopathological evaluation in differentiating psoriasis from eczema.

Methods

To confirm that the observed variability was not cohort- or rater-specific, a validation cohort (n = 72) from an independent institution was assessed by three dermatopathologists under identical conditions.

n = 72

Results

Molecular test sensitivity was 92.9%, versus 70% sensitivity for dermatopathologist evaluation - fewer missed diagnoses.

70%

Sensitivity

81.6%

Specificity

More results

Dermatopathological evaluation demonstrated only fair agreement (Fleiss' κ = 0.31) in both study and validation cohort.

The mean diagnostic accuracy of dermatopathology was 76.9%, with a sensitivity of 70% and specificity of 81.6%.

More results

In diagnostically ambiguous cases, molecular testing maintained high accuracy (>86%), clearly outperforming dermatopathology, which showed near-random agreement and low accuracy (61.7%).

“

Conclusion · 1 of 2

Both MC and PsorX-LabDisk provide a reliable, examiner-independent complement to dermatopathology for differentiating psoriasis and eczema.

Conclusion · 2 of 2

By reducing diagnostic ambiguity, it enhances clinical confidence and supports more precise and timely therapeutic decisions in inflammatory skin disease management.

Diagnostic concordance of dermatopathology and PCR in differentiating eczema from psoriasis.

Diagnostic concordance of dermatopathology and PCR in differentiating eczema from psoriasis.

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