Objective The objective of this study was to report the benefit of a therapeutic approach consisting of intravenous (IV) continuous anakinra (recombinant human interleukin‐1 receptor antagonist) infusions in treating severely ill adult patients with secondary hemophagocytic lymphohistiocytosis or macrophage activation syndrome (MAS). Methods A retrospective chart review of five patients treated at Regions Hospital from 2016 to 2019 was conducted. Demographic, clinical, and laboratory characteristics and outcomes were recorded. Results Continuous IV anakinra infusions up to 2400 mg/d resulted in rapid serologic, then clinical response in 4 of 5 severely ill patients who were refractory to all other therapies, including subcutaneous anakinra. Subsequently, 3 of 5 patients have been maintained on anakinra or canakinumab, with no recurrence of MAS. Conclusion Continuous infusion of IV anakinra may result in rapid serologic and subsequent clinical improvement in adult patients with MAS. This method for treating cytokine storm should be considered in the current COVID‐19 pandemic in the subgroup of patients with severe disease who have a cytokine storm presentation.

Susac syndrome is an immune-mediated, pauci-inflammatory, ischemia-producing, occlusive microvascular endotheliopathy/basement membranopathy that affects the brain, retina, and inner ear. Treatment of Susac syndrome is particularly challenging. The organs involved can easily become irreversibly damaged, and the window of opportunity to protect them is often short. Optimal outcome requires rapid and complete disease suppression. Adding to the challenge is the absence of objective biomarkers of disease activity and the great variability in presentation, timing and extent of peak severity, duration of peak severity, and natural disease course. There have been no randomized controlled trials or prospective treatment studies. We offer treatment guidelines based on cumulative clinical experience and a large cohort of patients followed longitudinally in a comprehensive database project. These guidelines state our preferences but do allow flexibility and discuss other options. The guidelines also serve as an initial step in the planning of prospective treatment studies, future consensus-based recommendations, and future randomized controlled trials.