If a child has no active disease present (doesn’t appear in labs and physical exams) but does have occasional morning and overuse stiffness, would that child be considered to have a higher risk of flaring up off medication? Would it be inadvisable to stop medication while experiencing stiffness?

At present, it is not known what factors- symptoms, lab tests, or disease type- put a patient at higher risk of flare off medication. Your doctor is the best to evaluate whether the symptoms you describe are due to active inflammation, or perhaps due to other issues.