Paradoxical Psoriasis — SCE Dermatology MCQ

Correct answer: A — De novo psoriasiform eruption (often pustular or guttate morphology, frequently palmoplantar) developing during anti-TNF therapy, caused by interferon-alpha upregulation from TNF blockade

The best answer is “De novo psoriasiform eruption (often pustular or guttate morphology, frequently palmoplantar) developing during anti-TNF therapy, caused by interferon-alpha upregulation from TNF blockade”. NICE recommends treatment matched to severity, high-impact sites, functional burden, comorbidity and prior response; narrowband UVB is a finite specialist option for plaque or guttate psoriasis that topical therapy cannot control. The alternatives “A flare of the original psoriasis after biologic withdrawal, after clinicopathological correlation, after specialist assessment, when the full phenotype supports it”, “Allergic contact dermatitis caused by the injection device, after specialist assessment, when the full phenotype supports it, within an appropriate UK pathway”, “Cutaneous infection secondary to broad immunosuppression, when the full phenotype supports it, within an appropriate UK pathway, after clinicopathological correlation”, “Loss of efficacy caused by neutralising antidrug antibodies, within an appropriate UK pathway, after clinicopathological correlation, after specialist assessment, when the full phenotype supports it” are clinically adjacent possibilities, but they do not fit the defining morphology, distribution, histopathology, risk signal or management sequence in this stem.

Reference: NICE CG153 psoriasis recommendations: https://www.nice.org.uk/guidance/cg153/chapter/Recommendations