Br J Dermatol. 2021 Sep 3. doi: 10.1111/bjd.20689. Online ahead of print.
ABSTRACT
BACKGROUND: In children, psoriasis can be challenging to diagnose. Difficulties arise from differences in the clinical presentation compared to adults.
OBJECTIVES: To test the diagnostic accuracy of previously agreed consensus criteria and develop a shortlist of best predictive diagnostic criteria for childhood psoriasis.
METHODS: A case-control diagnostic accuracy study in 12 UK dermatology departments (2017-2019) assessed 18 clinical criteria using blinded trained investigators. Children (<18 years) with dermatologist diagnosed psoriasis (cases n=160) or a different scaly inflammatory rash (controls n=170) were recruited. The best predictive criteria were identified using backward logistic regression and internal validation was conducted using bootstrapping.
RESULTS: The sensitivity of the consensus agreed criteria and consensus scoring algorithm was 84.4%, specificity was 65.1% and area under the curve (AUC) 0.75. Seven diagnostic criteria which performed best were: i) scale and erythema in the scalp involving the hairline; ii) scaly erythema inside the external auditory meatus; iii) persistent well-demarcated erythematous rash anywhere on the body; iv) scaly erythematous plaques on the extensor surfaces of the elbows and/or knees; v) persistent erythema in the umbilicus; vi) well demarcated erythematous rash in the napkin area involving the crural folds; vii) family history of psoriasis. Sensitivity of the best predictive model was 76.8%, specificity 72.7% and AUC 0.84. The c-statistic optimism adjusted shrinkage factor was 0.012.
CONCLUSIONS: This study provides examination and history-based data on the clinical features of psoriasis in children and proposes seven diagnostic criteria with good discriminatory ability in secondary care patients. External validation is now needed.
PMID:34477218 | DOI:10.1111/bjd.20689