Hypereosinophilic diseases represent a heterogeneous group that poses a significant medical challenge. An increased number of eosinophils in the blood can be a dominant symptom of hematologic diseases, such as myeloid hematopoietic cancers or lymphomas. However, it is more commonly associated with other health conditions, such as allergies, infections, and systemic inflammatory diseases. Distinguishing between eosinophilic vasculitis with polyangiopathy (EGPA) and idiopathic hypereosinophilic syndrome (I-HES) can be difficult in clinical practice. In this report, we provide practical guidelines for clinicians that may aid in the diagnosis and treatment of these diseases. Additionally, we discuss the role of biologic IL-5 inhibitors in their therapy, as mepolizumab is approved for the treatment of EGPA and I-HES. We believe that the proposed guidelines will be helpful for clinicians, especially those who are not familiar with hypereosinophilic diseases.
Keywords: biological treatment; eosinophilic vasculitis with polyangiopathy; eosinophils; glucocorticosteroids; hypereosinophilic diseases; idiopathic hypereosinophilic syndrome; mepolizumab.