Update on juvenile systemic sclerosis.

Juvenile systemic sclerosis is an orphan disease of the macro- and microvasculature with an unknown etiology. Although pediatric and adult classification systems have been developed, neither has been validated yet. Recent publications have shown a shift in the subset pattern in juvenile-onset adult patients, with a better outcome in these patients as compared with young adult patients. As a first step in assessing activity, damage, and severity, a pediatric severity score--a modification of the adult Medsger scale--was proposed but has not been validated. An activity score also has been developed but has not yet been published. Currently, treatment approaches are based only on adult data, and problems exist in extrapolating these data to a pediatric population.