Introduction: Idiopathic hypereosinophilic syndrome (IHES) is a rare immunological disorder, marked by peripheral blood eosinophilia without clear aetiology and can cause multiple organs/tissues damage from eosinophilic infiltration and mediator release. Stroke is a significant neurological complication of IHES and, therefore, it is important for stroke physicians, neurologists, and general physicians to recognise this rare condition early for effective treatment to prevent further multi-organs dysfunction.
Case presentation: We present a case of a 72-year-old man with IHES causing two major organs dysfunction after presenting with multifocal embolic stroke and myocardial injury. He initially presented with late onset features of right facial asymmetry, right arm weakness, dysarthria and expressive dysphasia. He has background history of intermittent peripheral blood eosinophilia with no apparent cause for approximately 2 years and had been extensively investigated by haematologist including normal bone marrow result, negative FISH panel, PDGFRA and negative JAK2 mutation. He had very severe eosinophilia (27.44 x 109/L) and biochemical evidence of myocardial injury in his first presentation to emergency department. MR brain confirmed multi-territory embolic infarcts with normal telemetry, echocardiogram, thrombophilia profile and autoimmune screen. He was urgently treated with high dose steroid, achieving good control of eosinophilia in few days. Outpatient cardiac MRI, after 8 weeks of prednisolone therapy, however, did not show evidence of myocardial injury. He is closely followed up in immunology clinic and there is no recurrent eosinophilia on successful steroid weaning course and 4 weekly benralizumab injection. He recovered well with minimal stroke deficits and is treated with direct oral anticoagulant therapy whilst monitoring IHES disease activity.
Conclusion: This case highlights the importance of achieving early diagnosis and effective treatment of this rare condition IHES to avoid further multi-organs dysfunction, morbidities and mortality.