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PubMed This is a summary of 19 peer-reviewed journal articles Updated
Hematology

Life After Diagnosis: Long-Term Monitoring and Flare Prevention

At a Glance

Living with Hypereosinophilic Syndrome (HES) requires lifelong monitoring to prevent organ damage. Patients need regular blood tests and echocardiograms to track the disease. Tracking daily symptoms helps identify flares early, allowing doctors to adjust treatments before complications occur.

Living with Hypereosinophilic Syndrome (HES) means transitioning from an acute medical crisis to a long-term “surveillance” mindset. Because HES is a chronic condition, staying in remission requires consistent monitoring and a proactive approach to your health [1][2].

Your Surveillance Schedule

While your doctor will tailor your schedule to your specific subtype, a typical monitoring plan often follows this general timeline:

  • Initial Phase (First 3-6 months): Frequent blood draws (every 1–4 weeks) to monitor your Absolute Eosinophil Count (AEC) and ensure your treatment is working [3][4].
  • Maintenance Phase: Once your counts are stable, blood tests may move to every 3–6 months [2].
  • Cardiac Monitoring: Because heart involvement can be “silent,” regular echocardiograms are essential. Even if you feel fine, your doctor may recommend a scan every 6–12 months to check for early signs of inflammation or thickening [2][5]. Cardiac MRI (CMR) may be used for a more detailed look if your echocardiogram is inconclusive [6][7].

Recognizing a Disease Flare

A “flare” occurs when your eosinophil counts rise and the disease becomes active again. Identifying these signs early can prevent new organ damage [8]. Watch for:

  • Skin Changes: New or worsening itchy rashes, hives, or painful sores in the mouth [9][10].
  • Respiratory Issues: A new, persistent cough or feeling short of breath during activities that were previously easy [9][11].
  • Neurological Warning Signs: New, severe headaches, unexplained confusion (“brain fog”), or sudden numbness/weakness in your limbs [12][13].
  • General Malaise: Profound fatigue, low-grade fevers, night sweats, or unexplained weight loss, which can be indicators of disease progression [8].

Managing Long-Term Treatment Side Effects

The medications that keep HES in check can have their own long-term impacts on your quality of life.

  • Corticosteroids: Long-term use can lead to bone thinning (osteoporosis) and adrenal suppression [14]. Your team should monitor your bone density with DEXA scans and may use “steroid-sparing” biologics like mepolizumab to help you lower your dose [15][8].
  • Imatinib: Common side effects include fluid retention (swelling around the eyes or ankles) and mild digestive upset [16]. These are often manageable with minor adjustments to diet or timing of the dose.
  • Biologics: These are generally well-tolerated, but your doctor will monitor for injection-site reactions or rare changes in your immune response [17].

Diet, Lifestyle, and Mental Health

While there is no specific “HES diet” that cures the disease, maintaining overall cardiovascular health through a balanced diet and manageable exercise helps reduce the strain on your heart and lowers the risk of blood clots.

“Scanning anxiety”—the stress that occurs before a blood draw or imaging test—is very common in rare disease patients. Many patients find it helpful to:

  1. Keep a Symptom Journal: This empowers you to provide accurate data to your doctor and notice patterns early [18].
  2. Coordinate Care: Ensure your hematologist, cardiologist, and primary care doctor are all receiving your test results [1].
  3. Establish a Flare Plan: Know exactly whom to call and what steps to take if your symptoms return [19].

Common questions in this guide

How often do I need blood tests when my HES is stable?
Once your eosinophil counts stabilize, your doctor may recommend blood tests every 3 to 6 months. During the first few months of treatment, you will likely need them much more frequently to ensure the medication is working.
Why do I need echocardiograms if I feel fine?
Hypereosinophilic syndrome can cause silent inflammation and thickening in the heart before you notice any symptoms. Regular echocardiograms every 6 to 12 months help detect this damage early so your treatment can be adjusted.
What are the warning signs of an HES flare?
Signs of a disease flare include new itchy rashes, a persistent cough, shortness of breath, severe headaches, unexplained confusion, or profound fatigue. Contact your care team immediately if you experience these warning signs.
How can I manage the side effects of long-term steroid use for HES?
Long-term corticosteroid use can lead to bone thinning, so your doctor will likely monitor your bone density with DEXA scans. They may also prescribe steroid-sparing biologic medications to help lower your required steroid dose.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.How often should I have my blood drawn to check my Absolute Eosinophil Count (AEC) now that I am stable?
  2. 2.Given my history, what is the recommended schedule for my follow-up echocardiograms?
  3. 3.If I am on long-term steroids, when should I have a DEXA scan to check my bone density?
  4. 4.What specific 'emergency' symptoms should trigger an immediate call to your office rather than waiting for my next appointment?
  5. 5.How will we monitor the effectiveness of my current treatment in preventing silent organ damage?

Questions For You

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References

References (19)
  1. 1

    Clinical Management of Persistent Hypereosinophilia.

    Helbig G, Czachor K

    European journal of haematology 2025; (114(5)):763-774 doi:10.1111/ejh.14396.

    PMID: 39961601
  2. 2

    Hypereosinophilic syndrome: cardiac diagnosis and management.

    Mankad R, Bonnichsen C, Mankad S

    Heart (British Cardiac Society) 2016; (102(2)):100-6 doi:10.1136/heartjnl-2015-307959.

    PMID: 26567231
  3. 3

    A case of hypereosinophilic syndrome with STAT5b N642H mutation.

    Ding F, Wu C, Li Y, et al.

    Oxford medical case reports 2021; (2021(1)):omaa129 doi:10.1093/omcr/omaa129.

    PMID: 33542831
  4. 4

    Long-term Follow-up of Severe Eosinophilic Hepatitis: A Rare Presentation of Hypereosinophilic Syndrome.

    Awadie H, Khoury J, Zohar Y, et al.

    Rambam Maimonides medical journal 2019; (10(3)) doi:10.5041/RMMJ.10373.

    PMID: 31335311
  5. 5

    Non-atherosclerotic myocardial infarction in hypereosinophilic syndrome: emerging insights and therapeutic approaches.

    Li J, Jia W, Li Q, et al.

    Heart (British Cardiac Society) 2025; doi:10.1136/heartjnl-2025-326273.

    PMID: 41207718
  6. 6

    Usefulness of Cardiac Magnetic Resonance in the Diagnosis of Löffler Endocarditis Secondary to Eosinophilic Granulomatosis with Polyangiitis.

    Kurokawa K, Sai E, Hayashi E, et al.

    Internal medicine (Tokyo, Japan) 2019; (58(2)):239-242 doi:10.2169/internalmedicine.1303-18.

    PMID: 30146590
  7. 7

    Case Report: An Unusual Presentation of Cardiovascular Involvement in Eosinophilic Granulomatosis With Polyangiitis.

    Li Y, Zhou H, Zhou Y, Tang H

    Frontiers in cardiovascular medicine 2022; (9()):928192 doi:10.3389/fcvm.2022.928192.

    PMID: 35837613
  8. 8

    Eosinophilia and wheeze: thinking beyond asthma.

    Kuek SL, Pettman C, Neeland MR, et al.

    Breathe (Sheffield, England) 2024; (20(1)):230126 doi:10.1183/20734735.0126-2023.

    PMID: 38482189
  9. 9

    Hypereosinophilic syndrome with multiorgan involvement: an interdisciplinary work-up.

    Looman KIM, Nuver ME, Korevaar TIM, Guillen SS

    BMJ case reports 2021; (14(2)) doi:10.1136/bcr-2020-240243.

    PMID: 33541953
  10. 10

    Idiopathic Hypereosinophilic Syndrome Presenting with Recalcitrant Oral and Genital Ulcers Responding Well to Thalidomide.

    Srinivas SM, Chebbi PG, Shivappa SK

    Indian dermatology online journal 2023; (14(5)):676-678 doi:10.4103/idoj.idoj_632_22.

    PMID: 37727572
  11. 11

    Cough in hypereosinophilic syndrome: case report and literature review.

    Xie J, Zhang J, Zhang X, et al.

    BMC pulmonary medicine 2020; (20(1)):90 doi:10.1186/s12890-020-1134-x.

    PMID: 32293378
  12. 12

    Teaching NeuroImages: Multifocal cerebral infarcts as a presentation of idiopathic hypereosinophilic syndrome.

    Wasilewski A

    Neurology 2019; (92(18)):e2178 doi:10.1212/WNL.0000000000007407.

    PMID: 31036582
  13. 13

    Idiopathic Hypereosinophilic Syndrome with Multiple Organ Involvement.

    Abo Shdid R, Azrieh B, Alebbi S, et al.

    Case reports in oncology 2021; (14(1)):249-255 doi:10.1159/000511396.

    PMID: 33776712
  14. 14

    Benralizumab for adults with rare and off-label eosinophilic disorders: a 52-week prospective, single-center study.

    Talmon A, Shamriz O, Rubin L, et al.

    Frontiers in immunology 2025; (16()):1702989 doi:10.3389/fimmu.2025.1702989.

    PMID: 41209013
  15. 15

    Real-world outcomes after anti-IL-5/anti-IL-5Rα treatment for hypereosinophilic syndrome: Systematic literature review.

    Jain P, Rowell J, Edmonds C, et al.

    The journal of allergy and clinical immunology. Global 2026; (5(1)):100608 doi:10.1016/j.jacig.2025.100608.

    PMID: 41488420
  16. 16

    A case of myeloid neoplasm with FIP1L1-PDGFRA rearrangement without marked peripheral blood eosinophilia.

    Wang J, Zhang Q, Zeng H, et al.

    Pharmacogenomics 2016; (17(2)):99-102 doi:10.2217/pgs.15.159.

    PMID: 26666578
  17. 17

    Response to a case report: Idiopathic hypereosinophilic syndrome in remission with benralizumab treatment after relapse with mepolizumab.

    Requena G, Roufosse F, Baylis LD, Steinfeld J

    Respirology case reports 2021; (9(2)):e00707 doi:10.1002/rcr2.707.

    PMID: 33425360
  18. 18

    Idiopathic Hypereosinophilic Syndrome: A Case Report.

    Agudo M, Santos F, Teixeira Reis A, et al.

    Cureus 2023; (15(6)):e39964 doi:10.7759/cureus.39964.

    PMID: 37416031
  19. 19

    Hypereosinophilic syndrome: a rare cause of ST-elevation myocardial infarction and thrombus formation on the aortic valve.

    Jørgensen MD, Schneider IR, Thomsen GN, Dahl JS

    BMJ case reports 2024; (17(4)) doi:10.1136/bcr-2023-259494.

    PMID: 38627047

This page provides general information about living with and monitoring Hypereosinophilic Syndrome (HES) for educational purposes. It does not replace professional medical advice, diagnosis, or a personalized surveillance plan from your hematologist or cardiologist.

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