BI26 More than skin deep: a case of eosinophilic fasciitis in a patient with relapsing–remitting multiple sclerosis

Abstract Eosinophilic fasciitis, also known as Shulman syndrome, is a rare variant of scleroderma that typically presents as symmetrical erythema, swelling and progressive induration of the extremities. It is characterized by fascial thickening with an eosinophilic inflammatory infiltrate and accompanying peripheral eosinophilia. Although the exact underlying aetiology remains unclear, an autoimmune mechanism targeting damaged fascia is presumed. Reported potential triggers include intense physical exertion, trauma, haematological malignancies and medications including immune checkpoint inhibitors, statins, tumour necrosis factor inhibitors, proton pump inhibitors and dopamine agonists. We describe the case of a 51-year-old woman who presented with a 6-month history of painful, progressive lower-limb oedema and erythema. She also reported tightness of the forearms but was otherwise well. Past medical history was notable for relapsing–remitting multiple sclerosis, which was well controlled for the past 3 years on ocrelizumab, a humanized anti-CD20 monoclonal antibody. She had no other regular medications. On examination, she had diffuse patchy erythema of the bilateral lower legs with associated subcutaneous nodularity and nonpitting oedema. She also had tethering at the right antecubital fossa and venous guttering. Investigations were notable for peripheral eosinophilia of 3.33 × 109 cells L−1 and an elevated C-reactive protein of 88 mg L−1. Histopathology from a deep incisional biopsy of the right calf showed a superficial and deep inflammatory infiltrate composed of numerous eosinophils, with extension to the subcutis and fascia. Magnetic resonance imaging demonstrated symmetrical bilateral upper- and lower-extremity subfalcine oedema. These findings supported a diagnosis of eosinophilic fasciitis. The patient was reviewed by rheumatology and commenced on a tapering regimen of prednisolone and methotrexate as a steroid-sparing therapy. She had a good clinical response with decreased discomfort of the extremities and normalization of her eosinophils within 4 weeks. Her disease remains well controlled on methotrexate 15 mg once weekly. While the development of eosinophilic fasciitis in this case was presumed to be idiopathic, to our knowledge, this is the first case of eosinophilic fasciitis developing in the setting of long-term ocrelizumab use.