Diagnostic value of piezogenic papules in childhood: A scoping review and analysis of existing data.

INTRODUCTION: Piezogenic papules (PP) are soft, skin-colored or yellowish herniations of subcutaneous fat appearing under pressure, commonly on the heels. While usually benign, they may cause pain and have been associated with Ehlers-Danlos syndrome. PP are included in the 2017 diagnostic criteria for hypermobile Ehlers-Danlos syndrome (hEDS), and in the 2023 framework for pediatric joint hypermobility, but their prevalence in healthy children and their clinical threshold remain unclear. AIM: To map current knowledge on the prevalence of PP in healthy children and adolescents and to analyze previously collected clinical data from healthy adolescents and those with Hypermobility Spectrum Disorder (HSD) or hEDS. METHODS: A scoping review was conducted. Peer-reviewed studies reporting PP prevalence or clinical characteristics in healthy children and adolescents (0-17 years) or including healthy controls were included. Additionally, clinical data from adolescents assessed for hEDS (2017 criteria) and healthy controls were analyzed descriptively. RESULTS: Of 707 identified articles, four observational studies and five case reports met the inclusion criteria. Across the reviewed studies, PP prevalence in children ranged from 16 to 72%, was generally asymptomatic. In the empirical cohort, PP were observed in 76% of individuals with HSD/hEDS and 60% in the control group, corresponding to a prevalence difference of 16% points (95% CI - 4 to 36; p = 0.163). CONCLUSION: PP are common and largely asymptomatic in children and adolescents. Although presumably more pronounced in individuals with HSD/hEDS, no statistically significant differences between groups were identified. Current evidence does not clearly support a diagnostic value, highlighting the need for further studies. TRIAL REGISTRATION: Open Science Framework - OSF. 2025 May 12. osf.io/8zp25 .