title: Hypereosinophilic syndrome.
abstract: BACKGROUND
  Hypereosinophilic syndrome (HES) is a myeloproliferative disorder characterized by persistent eosinophilia associated with multiple organ damage.
  
  
  OBJECTIVE
  To increase awareness of the rare but potentially life-threatening disease and to provide a brief overview of the clinical presentation, diagnosis, and management of HES.
  
  
  METHODS
  Pertinent data from the patient's clinical course was incorporated with salient articles on the topic.
  
  
  RESULTS
  A case of HES is presented, followed by discussion of the clinical characteristics, diagnosis, and management. Clinical pearls and pitfalls are emphasized for the practicing allergist, clinical immunologist, and fellow-in-training.
  
  
  CONCLUSIONS
  A diagnosis of HES should be considered in patients with an absolute eosinophil count of >1500 cells/μL documented on two occasions at least 1 month apart, and/or in those with pathologic confirmation of tissue hypereosinophilia. The decision to treat HES should be guided by both the clinical presentation and results of laboratory and mutational analysis.
authors.forename: Heung R
authors.initials: HR
authors.lastname: Noh
authors.forename: Gil G
authors.initials: GG
authors.lastname: Magpantay
mesh_terms: D019468:Disease Management; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012189:Retrospective Studies