Development of a clinical algorithm to predict phenotypic switches between atopic dermatitis and psoriasis (the “Flip‐Flop” phenomenon)

• DOI: 10.1111/all.15921
• Publication Date: 2023-10-21T07:03:31Z
• Authors: Svenja Müller; Thomas Welchowski; Matthias Schmid; Laura Maintz; Nadine Herrmann; Dagmar Wilsmann‐T...; Thorben Royeck; Regina Havenith; Thomas Bieber
• Keywords: Youden's J statistic; Atopy

Abstract Background Atopic dermatitis (AD) and psoriasis vulgaris (PV) are almost mutually exclusive diseases with different immune polarizations, mechanisms therapeutic targets. Switches to the other disease (“Flip‐Flop” [FF] phenomenon) can occur or without systemic treatment often referred as paradoxical reactions under biological therapy. Methods The objective was develop a diagnostic algorithm by combining clinical criteria of AD PV identify FF patients. prospectively validated in patients enrolled CK‐CARE registry Bonn, Germany. Afterward, refinements were implemented based on machine learning. Results Three hundred adult Caucasian included validation study ( n = 238 AD, 49 PV, 13 FF; mean age 41.2 years; 161 [53.7%] female). total scores groups differed significantly from group data p < .001). predictive generalized Youden‐Index initial model 78.9% [95% confidence interval 72.0%–85.6%] accuracy 89.7%. Disease group‐specific sensitivity 100% (FF), 95.0% (AD), 61.2% (PV). specificity 89.2% (PV), respectively. Conclusion represents first tool