Among the many rheumatic diseases MAS has been predominantly described associated with SoJIA. The next most common rheumatic illness described has been SLE. The hallmarks of this complication are Bone marrow suppression, DIC with abnormal bleeding, encephalopathy/ seizures, and hepatitis. MAS has been increasing been recognized to have similarities with Class II histiocytic disorders or hemophagocytic lymphohistiocytosis (HLH). In the most recent classification of these disorders Class II disorders have been further subdivided into primary (due to a genetic defect), secondary (due to infections, malignancies, immunodeficiency) and reactive (due to rheumatic diseases)8. The last category alludes to MAS.