Possible association of early - onset chondrodermatitis nodularis and risk of mortality. Results of a pilot retrospective case-control single-hospital study in Asturias, Northen Spain.

Abstract The long-term prognosis of patients with chondrodermatitis nodularis (CN) has never been investigated. We developed the empirical hypothesis that the survival of these patients could present differences with controls, based in our own previous experience. Our objective is to assess for the first time whether survival in CN patients and matched controls is similar. We investigated the number of natural deaths and survival in patients with histopathologically diagnosed early-onset (EO) (< 61 years at diagnosis) and late onset (LO) CN lesions (= > 61 years at diagnosis); and in matched age, gender and year of diagnosis controls in a Hospital in Asturias, North Spain (years 2000-2017). We have found a small, non-significant excess of mortality in the total CN sample (p= 0.14), but this excess was significant in patients with an early-onset (EO) (< 61 years at diagnosis) of CN lesions in: a) univariate analysis: OR = 6.3; IC: 1.1-44.4; p=0.02; b) Kaplan- Meier survival curve (log-rank test, p=0.02; c) and Cox proportional hazard model (HR for mortality, 5.93; p=0.03; CI: 1.20-29.41). In this pilot, empirical hypothesis - driven, matched, single-centre, case-control study, patients with EO CN lesions (before the age of 61 years) had a decreased survival respect to matched controls. The potential importance for patients of these results outweighs limitations (retrospective and single Hospital design; small number of events); and gives support for construction of multicentric investigations.