Differences evident between adults and children with SSc, study finds

Joint pain common in pediatric scleroderma patients, lung disease in older ones by Lindsey Shapiro, PhD 

The clinical presentation of systemic sclerosis (SSc) differs significantly between adult and pediatric patients, according to a recent study in Turkey.

Particularly, adults were more likely to have lung disease and to be at a higher risk of death than children, who were more likely to experience joint inflammation and pain. These differences, in turn, influenced treatment choices, which diverged significantly between adults and children.

The study, “Juvenile and adult-onset scleroderma: Different clinical phenotypes,” was published in the journal Seminars in Arthritis and Rheumatism.

​Study of 151 adult-onset SSc patients and 30 with juvenile onset
SSc, also known as scleroderma, is marked by the accumulation of scar tissue in the skin and other organs. While it can affect individuals at any age, the disease typically emerges between the ages of 20 and 50.

Juvenile disease onset is rare, accounting for somewhere between 1.5% and 11.5% of all SSc cases, according to the researchers. Most children will have a localized form of scleroderma that mainly affects the skin.

Because of this, data related to how SSc manifests in children are limited, and few studies have directly compared disease presentation between pediatric- and adult-onset forms of the disease.

To address that knowledge gap, researchers compared disease features between 151 people with adult-onset SSc and 30 with pediatric-onset disease seen at their Istanbul center between 1996 and 2018.

Adult patients had a mean age of 42 at disease diagnosis, whereas pediatric patients were diagnosed at a mean of 10.4 years old. The mean duration of follow-up was more than six years in both groups.

Interstitial lung disease (ILD), marked by lung inflammation and scarring, was significantly more common among adults with SSc (50.9%) than children (30%).

Only adults had high blood pressure. Older patients also were more likely to be positive for Scl-70 self-reactive antibodies, a type of scleroderma-associated autoantibody.

Children were more likely to have arthritis — joint inflammation — and arthralgia (joint pain) compared with their adult counterparts. Specifically, 33.3% of children and 21.8% of adults had arthritis, and 60% of children and 20.5% of adults had arthralgia.

That finding could be due to a “lower tolerance threshold in [the] pediatric population,” the researchers wrote.

Moreover, children were significantly more likely to have ulcers on their fingers, a common SSc manifestation.

Other organ involvement, including that affecting the heart and the kidneys, was more common in adults, but these differences failed to reach statistical significance. The scientists said this could be due to the study’s small number of patients.

About three-quarters of the children had the diffuse cutaneous SSc subtype, while about three-quarters of the adults had limited cutaneous SSc.

Vital organs more likely to be affected by disease in adults
Some differences in SSc treatment were also noted between the two groups, with adults more likely to use calcium channel blockers, angiotensin-converting enzyme inhibitors, prostaglandin analogs, phosphodiesterase 5 inhibitors, rituximab, and aspirin.

Children more frequently used glucocorticoids or methotrexate.

Adults had a significantly higher mortality rate than the juvenile group and a significantly shorter survival. Particularly, 15.9% of adults died over the course of follow-up as did one child.

The researchers believe that finding might be explained by the higher incidence of vital organ involvement among adults with SSc.

Consistently, a statistical analysis showed that ILD and cardiac insufficiency were independent risk factors for death across the entire group of adult and pediatric patients.

A smaller group of seven adults and 28 children seen at the clinic had localized scleroderma, a form restricted to the skin, reflecting a significantly higher proportion of pediatric scleroderma patients with localized disease.

All localized scleroderma patients were alive throughout a mean follow-up of more than seven years.
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Findings overall indicate a “significant difference in clinical presentations” between adult and pediatric patients, the researchers wrote. “Prospective studies with longer follow-up and higher [patient numbers] are required to confirm our findings.”