Localized Scleroderma Cutaneous Assessment Tool (LoSCAT) adapted for use in adult patients: report from an initial validation study

Background: Localized scleroderma (LoS) affects both children and adults and is associated with permanent functional and cosmetic impairment, and reduced quality of life predominating in adults. The Localized Scleroderma Cutaneous Assessment Tool (LoSCAT) is a clinical instrument designed to measure an activity and damage of LoS. It has been validated for use with pediatric LoS patients. This study assessed the validity and reliability of the LoSCAT adapted for use in adults. Methods: Before the initiation of the study two examiners participated in an intensive training course carried out by an expert in LoS. Appendices describing each LoSCAT domain were prepared. Features determining disease activity and damage in adult LoS patients were identified to properly evaluate the physician (Phys) and patient (Pt) global assessment (GA) of disease activity (A)/severity (S) and damage (D), which were used to assess convergent validity of the LoSCAT. Correlations of physician- and patient-derivied measures with Skindex-29 were also analysed. Results: The study included 40 adult LoS patients (33 females and 7 males) with different subtypes of LoS. Intra and inter-rater reliability of the LoSCAT was found to be excellent. Positive correlations were observed between the PhysGA-A, PhysGA-D, PtGA-A and the LoSCATs domains, while no correlations between them and the PtGA-D were found. There were no relationships between LoSCAT's components and Skindex-29. Conclusions: Despite the LoSCAT is a reliable tool for an assessment of cutaneous lesions, additional health status instruments are necessary to a holistic approach to LoS in adults.