005 Idiopathic hypereosinophilic syndrome as a cause for digital ischaemia in a patient with Raynaud’s phenomenon and ankylosing spondylitis

Abstract

Background: Idiopathic hypereosinophilic syndrome (HES) is a rare hematological disorder (estimated European prevalence 1.5/100,000) believed to result from overproduction of eosinophilopoietic cytokines. End-organ damage results from eosinophilic infiltration of tissues and inflammatory mediator release from eosinophilic granules. Mortality may occur secondary to eosinophilic endomyocardial involvement with subsequent fibrosis. Method(s): We retrospectively outline the presentation and management of a 66-year-old male with a background history of ankylosing spondylitis and non-ulcerating Raynaud's phenomenon presenting with bilateral acrocyanosis and digital ischaemia with markedly elevated eosinophils. Result(s): A 66-year-old non-smoking male with a background history of ankylosing spondylitis, Raynaud's phenomenon and autoimmune thrombocytopenic purpura, presented to the emergency department with acrocyanosis of the 2nd and 3rd digits on the left hand. The patient had been diagnosed with autoimmune thrombocytopenic purpura two months prior to presentation and successfully treated with oral dexamethasone and transexamic acid. Three weeks following the onset of acrocyanosis the patient's symptoms deteriorated rapidly, with significant ischaemia of the 2nd and 3rd digits and extension of acrocyanosis to the other digits and contralateral limb. Initial treatment with intravenous iloprost, led by the vascular surgery service, did not lead to clinical improvement. The patient was subsequently transferred to the rheumatic diseases unit, Edinburgh, for further investigation and management. Review of the patient's haematological profile for the weeks prior to presentation revealed a progressive elevation in eosinophil count to a zenith of 14 x103/mL. Extensive autoimmune serology testing was negative. Bone marrow examination revealed evidence of a reactive eosinophilia but no presence of a clonal myeloproliferative neoplasm. Upper-limb CT-angiography led to the detection of bilateral ulnar artery occlusions with preserved microvascular circulation. Further examination of the arterial tree including CT-aortogram and transthoracic echocardiography revealed a dilated aortic root but no evidence of a source of thromboembolism or infective endocarditis. A diagnosis of acute digital ischaemia secondary to bilateral ulnar artery occlusion resulting from hypereosinophilic syndrome was made. The patient received pulse intravenous methylprednisolone (500mg) for three days and was discharged on a tapering dose of 60mg oral prednisolone. An immediate fall in circulating eosinophil levels occurred following steroid initiation and full resolution of the digital ischaemia occurred over a three-month period. Conclusion(s): The importance of macrovascular circulation assessment in patients with digital ischaemia secondary to Raynaud's phenomenon cannot be underestimated. This is particularly relevant in patients where previous Raynaud's phenomenon is mild and nonulcerating. In this case, upper-limb CT-angiography led to the detection of bilateral ulnar artery occlusions with associated elevation in eosinophil levels. A diagnosis of hypereosinophilic syndrome was made on this basis and the patient made a full recovery following corticosteroid treatment.