['Systemic mastocytosis is a clonal myeloproliferative neoplasm associated with constitutional symptoms from mast cell mediated chemical and cytokine release. According to the literature, Ruxolitinib, a JAK1/JAK2 inhibitor, has been shown to reduce symptoms related to proinflammatory cytokine release in other myeloproliferative neoplasms.', 'Here we present a case using Ruxolitinib for disabling constitutional symptoms despite complete bone marrow response in a patient with aggressive systemic mastocytosis. Assessment tools used to monitor symptoms in previously published Ruxolitinib trials were adopted to track symptom improvement and quality of life.'] Does ruxolitinib improve symptoms and quality of life in a patient with systemic mastocytosis?