Hypereosinophilic syndrome (HES) is a rare disease with diverse clinical presentation that is a diagnosis of exclusion1

Patients with HES are characterized by1,2:

  • Sustained hypereosinophilia (AEC ≥1500 cells/µL on 2 examinations ≥2 weeks apart)
  • Hypereosinophilia and eosinophil-mediated organ damage/dysfunction not caused by other conditions*

In patients with HES, eosinophilic inflammation leads to organ damage—often in more than one organ system.2

Patients with HES present with a range of clinical symptoms†‡3

Medical infographic describing eosinophilic inflammation and disease progression in Hypereosinophilic Syndrome (HES) Medical infographic describing eosinophilic inflammation and disease progression in Hypereosinophilic Syndrome (HES)

More than 50% of patients exhibited damage in ≥3 organ systems in a retrospective study§4

In patients with HES, eosinophilic inflammation leads to organ damage—often in more than one organ system.2

*Other conditions may include allergies, infections, or autoimmune disorders.1,2

†Percentages reflect the proportion of surveyed U.S. respondents with self-reported HES who endorsed specific symptoms in a one-time, 104-item online questionnaire administered via APFED (February–May 2022). Symptoms are not mutually exclusive. Figures represent descriptive, patient-reported data and may be subject to recall bias.3

‡Symptom category labels align with domain names from the survey as follows: cardiovascular=circulatory symptoms; dermatologic=integumentary symptoms; gastrointestinal=digestive symptoms; musculoskeletal=muscular symptoms; neurologic=nervous system symptoms; pulmonary=respiratory symptoms.3

§Based on data from a real-world retrospective study on disease burden and clinical characteristics in patients with idiopathic HES (I-HES) or lymphocytic HES (L-HES).4

AEC, absolute eosinophil count; APFED, American Partnership for Eosinophilic Disorders.