Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) presenting as diffuse myositis

Abstract

BackgroundEosinophilic granulomatosis with polyangiitis is a complex multisystemic syndrome with heterogeneous presentation. Most often, there is a clinical history of asthma or other atopic conditions, and current presentation generally includes signs of cutaneous or pulmonary involvement. Very few reports described myalgia or weakness as the chief complaint. Of these, only a few included muscle biopsy evaluation and none showed convincing evidence of primary myositis. We believe this report is the first to demonstrate true myositis in the setting of early eosinophilic granulomatosis with polyangiitis.Case presentationThis report describes a 74 year old Caucasian man, with no known allergies, presenting severe myalgia, muscle weakness, jaw claudication, and fever. Blood work showed marked eosinophilia and high creatine kinase levels. Biceps brachialis muscle biopsy revealed eosinophilic necrotizing vasculitis and true myositis with myophagocytosis of non-necrotic fibers and strong sarcolemmal MHC-1 overexpression by immunohistochemistry. This patient was successfully treated with prednisone and azathioprine.ConclusionOur finding of true myositis in a case of eosinophilic granulomatosis with polyangiitis suggests that primary auto-immunity against muscle fibers, distinct from the secondary effects of vasculitis, can occur in this entity and may represent an overlap syndrome. Early recognition of eosinophilic granulomatosis with polyangiitis in patients presenting with myositis may provide an opportunity to treat the vasculitis before onset of severe multisystemic disease. We recommend the use of muscle biopsy with immunohistochemistry for MHC-1 to confirm the diagnosis of myositis in the setting of eosinophilic granulomatosis with polyangiitis.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2474-15-388) contains supplementary material, which is available to authorized users.

A Case of Myositis Preceding Neuropathy in Eosinophilic Granulomatosis with Polyangiitis

“…There have been few case reports of inflammatory myopathy in EGPA, and only one recurrent myositis case included a detailed description on muscle pathology. 3 MR images together with muscle pathology in our case confirms the presence of vasculitis in skeletal muscle. It is interesting that one retrospective study found proximal limb weakness in 6 of 24 EGPA patients with peripheral neuropathy had proximal limb weakness, which might have been concomitant skeletal muscle involvement that was overlooked clinically.…”

Secondary myopathy due to systemic diseases

“…It manifests clinically in three stages, initially as allergic cold and asthma, followed by eosinophilic infiltration of the lung and intestines and systemic vasculitis. Myositis is a rare muscle manifestation of the disease and presents with myalgia, fever, and muscle weakness . Myositis in Churg–Strauss syndrome may not only concern all muscles resulting in polymyositis but may occur focally as orbital myositis .…”

Anti-neutrophil Cytoplasmic Antibody-associated Vasculitis (AAV) Restricted to the Limbs

“…One suggestive case report by Parent et al described a case of eosinophilic granulomatosis with polyangiitis (EGPA) presenting as diffuse myositis. In that report, a muscle biopsy showed necrotizing vasculitis with true myositis ( 46 ), and the main location of inflammation was thought to be both the vessels that supply the muscles and the muscle itself. Our case shows that both perimysial and endomysial infiltration of neutrophils can accompany vasculitis ( Fig.…”