[Hypereosinophilic syndrome, case report and diagnostic approach].

Background: Hypereosinophilic syndrome (HES) is a rare hematological disorder, characterized by blood and tissue eosinophilia, causing tissue damage and dysfunction. The onset of the disease is generally asymptomatic, being discovered incidentally. The objective of this article is to illustrate the rare clinical presentation in patients with chronic kidney disease. Clinical case: A 69-year-old male patient, with a history of type 2 diabetes and high blood pressure, was admitted to the internal medicine service with wasting syndrome under study, multiple urticarial skin lesions and peripheral blood cytopenias. During the approach to him, eosinophilia of more than 5.0 × 109 / L was evidenced, a bone marrow aspirate was performed, which revealed eosinophilic infiltration with dysplasia, biopsy of dermal lesions with mixed cellular infiltrate with a predominance of eosinophils; With the above, the diagnosis of idiopathic HES is made, after the exclusion of other evident eosinophilia etiologies. Systemic steroid treatment was started. Conclusions: Eosinophilic disorders represent a heterogeneous group of rare conditions, with multiple clinical manifestations, predominantly dermatological. An important association with the development of chronic kidney disease is reported, so a comprehensive approach must be carried out, with the aim of achieving an etiological diagnosis that allows early treatment and improves survival.