What Is Special About Juvenile Systemic Sclerosis?
We must remember that kids are not just “little adults.”
This applies for many of the autoimmune diseases that pediatric rheumatologists treat, including systemic sclerosis. (The terms, “Pediatric Systemic Sclerosis,” and “Juvenile Systemic Sclerosis,” are used interchangeably.)
Children are growing, and manifestations of scleroderma, or systemic sclerosis, may present differently. In addition, children tend to adapt and not complain, therefore sometimes the doctor has to order additional studies or evaluations to really understand what is happening inside the body.
One prime example would be that children with systemic sclerosis typically have what pediatrician’s call “failure to thrive” in which their weight, body mass index, and height is not keeping up with the normal expected development. Although the child might not have frank weight loss, they are not gaining weight appropriately. This could be because the immune system is too busy attacking itself, causing skin, muscle and joint, and gut changes.
What Is the Incidence and Prevalence of Systemic Sclerosis in Youth Compared to Adults?
Of all the people with systemic sclerosis, juvenile onset accounts for only 5-10% of all cases. Juvenile onset systemic sclerosis is 10x less common than juvenile localized scleroderma. The estimated incidence rate is only 0.27 per million children per year, with an estimated annual prevalence of 2 to 4 children per 1,000,000 children. This estimates approximately 300 children in the United States of America diagnosed with systemic sclerosis.
The mean age of disease onset in juvenile systemic sclerosis (jSSc) is approximately 8 to 11 years old.
Like adult-onset systemic sclerosis, there is a female predominance in juvenile-onset, with a ratio of 4:1 females:males and frequency of 76 – 84% females in the larger international jSSc cohort studies.
What Is the Difference in Disease Progression Between a Youth Patient and an Adult Patient?
Like adult onset, juvenile systemic sclerosis can involve almost every organ system and can range from mild to severe. We would encourage you to review some of the patient education material regarding the general features of systemic sclerosis throughout this website.
The most common organ systems affected in children with systemic sclerosis are:
- Skin, musculoskeletal, vascular (Raynaud’s and digital ulcer), and gastrointestinal (70 – 100%)
- Followed by pulmonary (interstitial lung disease) (30 – 45%)
- Less commonly cardiovascular (including pulmonary arterial hypertension) and renal involvement (4 – 15%)
- Only very rarely neurological (<1%)
Notably different between the juvenile and adult onset systemic sclerosis is the overall survival rate, which is much more favorable in juvenile onset disease. This has been supported by more recent pediatric systemic sclerosis International cohort studies.