<h3>Introduction</h3> Hypereosinophilia has numerous potential etiologies with the risk of end-organ damage and significant morbidity. The workup can be challenging in the setting of complicated medical and social histories and requires a broad differential. <h3>Case Description</h3> A 26 year-old woman with a history of Evans Syndrome (autoimmune hemolytic anemia with immune thrombocytopenia), juvenile dermatomyositis, moderate persistent asthma, and allergic rhinitis presented to Allergy clinic for evaluation of hypereosinophilia. Approximately 6 months prior to presentation to Allergy clinic, the patient experienced a sharp sustained rise in absolute eosinophil count (AEC), increasing from a baseline of 300 cells/mcL to a peak of 3100 cells/mcL. The timing of eosinophilia coincided with ongoing Evans Syndrome management requiring obinutuzumab and romiplostim as well as routine marijuana usage. The patient was asymptomatic during this time apart from a self-limited flare in asthma symptoms following inhaled marijuana. The differential included standard etiologies as well as consideration of marijuana (or contaminant) hypersensitivity and/or drug reaction to a novel biologic medication. Laboratory and radiographic evaluations were extensive, though ultimately inconclusive, and the patient's AEC spontaneously normalized with ongoing inhaled marijuana avoidance and deferral of obinutuzumab and romiplostim. <h3>Discussion</h3> We present this case to demonstrate novel exposures which may have precipitated an uncommon cause of hypereosinophilia. We hope this may provide insight into evaluating patients with unclear causes of hypereosinophilia, especially as exposures to marijuana and biologic medications continue to grow.