Specific Features of Active Disease in Juvenile Localized Scleroderma Identified in Study

Specific features of lesions associated with active disease in juvenile localized scleroderma — such as redness but not skin thickness — were identified in a study, and its researchers suggest they may be used to assess disease activity in young patients.

The findings may be the first step toward a specific, sensitive, and responsive tool to measure disease activity in pediatric scleroderma patients, improving care.

The study, “New Features for Measuring Disease Activity in Pediatric Localized Scleroderma,” was published in The Journal of Rheumatology.

Localized scleroderma causes scarring in the skin and underlying tissues — such as muscle, bones, and joints — and is the most common form of scleroderma in children. It can lead to deformities, severe limb atrophy, and functional disabilities in growing children, who often have persistently active disease or relapses into adulthood.

Researchers in the U.S., Canada, and Germany identified a set of clinical features specific to active disease in juvenile localized scleroderma.

They analyzed the features of a single lesion in 90 patients (71 girls and 19 boys), with a mean age of 7.9 at disease onset. Most  (61%) had linear scleroderma, a subtype of localized disease that spreads in thick streaks along the skin, usually on the arms or legs, but also on the torso.

Sixty-six patients had active disease and 24 inactive disease, according to their treating physicians. Disease activity was also assessed through the physician’s global assessments of activity (PGA-A), which included scores of activity of the study lesion and of a patient’s overall disease.

Lesion features most commonly reported  as indicative of active disease were redness (62%), hard and dense bump (51.5%), tactile warmth (36%), and lesion extension (33%). A distinct border; development of a new lesion; violaceous (dark red or purple), white, de-colored, and dark color lesions were also cited.

Next, the team analyzed the features of a single lesion — the most active, readily evaluable lesion in patients with active disease, and any lesion in those with inactive disease — at three visits, and their association to the patient’s PGA-A scores.

Results showed that no single feature common to active lesions, but redness, violaceous color, disease extension, tactile warmth, and abnormal skin texture were specific to active disease. These features were more frequent and showed higher scores (for redness and violaceous color) in active lesions, and were linked to worse PGA-A scores, with similar changes seen over time.

Such findings suggest that these lesion features — the combination of redness, disease extension, violaceous color, skin thickening, and abnormal skin texture — could be used to assess disease activity and predict PGA-A scores. Redness of the skin had the strongest association with PGA-A scores.

The presence of skin thickening (usually associated with active disease) and the presence of damage features, such as atrophy and de-coloration (usually associated with inactive disease), were not found to adequately distinguish active from inactive lesions.

“Our study provides important information for clinicians caring for patients with pediatric LS [localized scleroderma], including the lack of a universal activity feature and lack of specificity of skin thickness for active disease,” the researchers wrote.

They concluded their findings should “facilitate development of a sensitive, specific, and responsive activity tool” with the potential to “improve care, enable controlled treatment trials to be conducted, and improve long term outcomes for this often severely damaging disease.”