Trained in both adult and pediatric rheumatology at HSS over 30 years ago and prior to that, having the privilege of working with the late Professor John Baum, gave me the opportunity and challenge of seeing and managing many children with SS.
As you are likely aware, the EBM in this area is minimal, and one is left with predominantly n of 1 trials. Certainly, there is no strong data that anyone pharmacological approach works best for all the manifestations of PSS.
Whether the predominant clinical issue is impending ischemia from severe Raynauds, encasement of fibrosing cutaneous involvement, ILD, pulmonary hypertension, microangiopathic anemia, ARF, cardiac involvement or GI involvement - any of these individually or in combination requires empiric therapy and individualized clinical judgement , in my humble opinion, as EBM alone is inadequate to algorithmically address these medical issues or the psychosocial and nutritional issues that are concurrent and important co-morbidities. Other than the Up To Date Resource available via many Health Science Library licenses or personal subscription, the best (and freely available summary on all classes of interventions is via Medscape's formerly emedicine link I provide you below, I hope you find it useful for your specific needs as a starting point.