title: Eosinophilic myositis: an updated review.
abstract: Eosinophilia-associated myopathies are clinically and pathologically heterogeneous conditions characterized by the presence of peripheral and/or muscle eosinophilia. There are at least three distinct subtypes: focal eosinophilic myositis, eosinophilic polymyositis, and eosinophilic perimyositis. Infiltrating eosinophils are not always identified in conventional muscle histologic examination, but the eosinophil major basic protein, whose extracellular diffusion is considered a hallmark of eosinophilic cytotoxicity, is usually detected by immunostaining in muscle biopsy. Whereas focal eosinophilic myositis seems to be a benign and isolated condition, and perimyositis is usually related with the inflammatory infiltrate due to fasciitis, eosinophilic polymyositis can be associated with muscular dystrophy or be a feature of multiorgan hypereosinophilic syndrome. Muscle biopsy remains the cornerstone for the diagnosis. Parasitic infections, connective tissue disorders, hematologic and non-hematologic malignancies, drugs, and toxic substances are the main etiologic agents of eosinophilia-associated myopathy. However, in some cases, no known etiologic factor is identified, and these are considered idiopathic. Glucocorticoids are the mainstay therapy in idiopathic forms. Imatinib and mepolizumab, a humanized anti-interleukin 5 monoclonal antibody, may be useful in patients with eosinophilic myositis as part of a hypereosinophilic syndrome.
authors.affiliation: Internal Medicine Service, Hospital Vall d'Hebron, Universitat Autonoma de Barcelona, Barcelona, Spain. Electronic address: aselva@vhebron.net.
authors.forename: A
authors.initials: A
authors.lastname: Selva-O'Callaghan
authors.affiliation: Internal Medicine Service, Hospital Vall d'Hebron, Universitat Autonoma de Barcelona, Barcelona, Spain. Electronic address: ernesto_trallero@hotmail.com.
authors.forename: E
authors.initials: E
authors.lastname: Trallero-Araguás
authors.affiliation: Muscle Research Unit, Internal Medicine Service, Hospital Clínic de Barcelona, Villarroel 170, 08036 Barcelona, Spain; Fundació Cellex, University of Barcelona, Villarroel 170, 08036 Barcelona, Spain. Electronic address: jmgrau@clinic.ub.es.
authors.forename: J M
authors.initials: JM
authors.lastname: Grau
mesh_terms: D000906:Antibodies / Q000627:therapeutic use; D004802:Eosinophilia / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D005938:Glucocorticoids / Q000276:immunology; D006801:Humans; D015848:Interleukin-5 / Q000276:immunology; D049288:Muscular Dystrophies, Limb-Girdle; D009220:Myositis / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D017285:Polymyositis / Q000175:diagnosis / Q000628:therapy
chemical_list: D000906:Antibodies; D005938:Glucocorticoids; D015848:Interleukin-5
keywords: Eosinophil; Eosinophilia-associated myopathies; Eosinophilic myositis