Hypereosinophilic Syndrome Follow-up

Updated: Oct 14, 2020
  • Author: Venkata Anuradha Samavedi, MBBS, MD; Chief Editor: Emmanuel C Besa, MD  more...
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Hypereosinophilic syndrome has many and varied complications. Their development depends entirely on which organ systems are involved in the disease process (see Presentation and Pathophysiology). The most serious complication of hypereosinophilic syndrome is cardiac involvement, which can lead to myocardial fibrosis, chronic heart failure, and death (see Pathophysiology).



Hypereosinophilic syndrome carries a variable prognosis. It is a chronic and progressive disorder that is potentially fatal if left untreated. Blast transformation may occur after many years.

Although initial studies of hypereosinophilic syndrome showed a very poor prognosis (a 3-y survival rate of 12%), [4] management of cardiovascular disease by early echocardiographic monitoring and advances in medical and surgical therapies have improved the overall survival. A study of 40 cases by Lefebcve et al showed a 5-year survival of 80% and a 15-year survival of 42%. [19]

The availability of tyrosine kinase inhibitors such as imatinib, which prevent progression of cardiac disease and other organ damage—particularly in FIP1L1/PGDFRA–positive cases—will likely further improve the prognosis of hypereosinophilic syndrome. However, FIP1L1/PGDFRA– negative cases of hypereosinophilic syndrome that are resistant to corticosteroids have not been shown to have a durable response to imatinib.

Lastly, additional insight into the molecular pathogenesis of such cases of hypereosinophilic syndrome is required to develop effective targeted therapies.

Features that indicate a favorable prognosis in hypereosinophilic syndrome include the following:

  • Angioedema
  • Urticaria
  • Elevated serum IgE level
  • Sustained response to corticosteroids
  • Early diagnosis and intensive management

The presence of features that are suggestive of myeloproliferative disorder (MPD) and leukocytosis greater than 90,000/μ L carry a worse prognosis in hypereosinophilic syndrome.


Long-term Monitoring

Periodically observe patients with hypereosinophilic syndrome to confirm that the eosinophilia is controlled and that no evidence of new or worsening organ involvement occurs. Patients should be advised to report any new or worsening symptoms.

Follow up patients with hypereosinophilic syndrome with serum troponin levels every 3 months, as well as with echocardiograms and pulmonary function tests every 6 months.