Pneumonia and seizures due to hypereosinophilic syndrome—organ damage and eosinophilia without synchronisation: A case report

BACKGROUND: Hypereosinophilic syndrome (HES) is a condition characterized by increased eosinophil proliferation in the bone marrow, as well as tissue eosinophilia, often causing organ damage. The cause of the disease is unknown. Initial symptoms include fatigue, cough, shortness of breath, myalgia, angioedema, fever, and pneumonia. In addition to the respiratory symptoms, damage to the central nervous system can lead to severe seizures. Here, we report a case with pneumonia and complex partial seizures secondary to HES. CASE SUMMARY: A 94-year-old woman was admitted to our hospital for heart failure and bloody stools. After admission, she also showed symptoms of pneumonia. Non-contrast computed tomography of the chest showed pleural effusion and infiltrative shadows. Lower gastrointestinal endoscopy showed multiple ulcers in the sigmoid colon. Blood analyses showed marked eosinophilia (eosinophils 1760/mm(3), total leukocytes 6850/mm(3)). Initial treatment with furosemide 20 mg/d and prednisolone 25 mg/d relieved these symptoms. However, the patient subsequently experienced localised epileptic seizures characterized by bilateral eyelid twitching and eyes rolling upwards, without generalized convulsions, and respiratory arrest occurred. Electroencephalography showed spikes and waves. Non-contrast magnetic resonance imaging of the brain showed extensive periventricular hyperintensity. With administration of levetiracetam 1000 mg/d the epileptic seizures disappeared. However, the patient’s consciousness remained impaired, and her pneumonia worsened again. Two weeks later, she died of pneumonia. CONCLUSION: HES symptoms are variable and atypical, and the level and timing of eosinophilia and organ damage are often discordant.