Case Presentation: An 18-year-old female with no medical history was evaluated at an outside hospital for erythematous rash on her forearms, abdominal pain, chest pain, and leukocytosis. Chest Computed Tomography revealed hilar adenopathy. Transthoracic echocardiography showed right atrial and right ventricular (RV) dilation with low ejection fraction (EF). She was then transferred to our institution. Repeat history obtained when she arrived at our institution noted she developed urticaria and bronchitis in the past month, was found to have incidental leukocytosis and was undergoing outpatient evaluation for lymphoma with a pending lymph node biopsy. Family history disclosed paternal asthma. Physical exam demonstrated tachycardia, lower extremity edema and decreased breath sounds. Lab evaluation yielded WBC count of 26,000 with 42% eosinophils, troponin of 11.26 (Reference < 0.11 ng/mL) and brain natriuretic peptide of 146. EKG showed T wave inversions diffusely. Cardiac Magnetic Resonance Imaging showed RV dilation with EF < 20%. Bone marrow biopsy showed >40% eosinophils with no abnormal blasts. Right heart catheterization yielded no shunt or pulmonary hypertension. Infectious workup was negative. Lymph node biopsy was reactive with no malignancy. Concerned for hypereosinophilic syndrome with systemic involvement high dose steroids were initiated with significant decline in eosinophil count. Hospital course was complicated by dyspnea, cough, and abdominal pain all of which resolved with initiation of steroids. She was discharged home with prednisone, hydroxyurea, and outpatient hematology follow-up.Over the next year, the patient had multiple emergency department visits for bronchitis, dyspnea and chest pain treated with IV steroids. Unfortunately, 1.5 years after the patient’s index admission the patient suffered cardiopulmonary arrest and passed away.
Discussion: Eosinophilia, occur in 1% to 2% of the general population, while hypereosinophilia (HE), defined as counts ≥1.5 × 10^9/L, is exceptionally rare. Various causes, including allergies, infections, cancers, genetics, and immune issues, lead to diverse symptoms impacting different organs. Diagnosis relies on a comprehensive assessment involving medical history, physical examination, prior blood tests, medications, travel history, cancer risks, and family history. Initial tests cover blood counts, chemistries, immunoglobulin levels, B12, tryptase, lymphocyte assessment, and helminth testing if relevant.Hypereosinophilic syndrome (HES) refers to hypereosinophilia & end-organ dysfunction secondary to the hypereosinophilia. HES is subdivided into 6 subtypes: 1. Myeloid HE/HES2. Lymphocytic variant HE/HES3. Overlap HES4. Associated HE/HES (e.g., helminth infection or neoplasm)5. Familial HE/HES6. Idiopathic HE/HESCorticosteroids remain the primary treatment for HES, but newer targeted therapies are increasingly replacing traditional immunosuppressive agents.
Conclusions: Hypereosinophilic syndrome (HES) is defined as hypereosinophilia & end-organ dysfunction. HES is group of rare disorders with a multitude of clinical manifestations. A focused clinical evaluation to identify end-organ manifestations & the clinical subtype of HES is imperative for both therapeutic and prognostic reasons. Early recognition of this rare disorder is imperative, thus, HES should be in clinicians’ differential if confronted with hypereosinophilia.