Absence of Coxsackie viruses in idiopathic inflammatory muscle disease by in situ hybridization

Masticator myopathy

A 31-year-old woman developed low-grade fever and pain and swelling of the masticatory muscles. A T2-weighted magnetic resonance image showed high signal intensity in these muscles. Coxsackie B3 and echo 30 viruses were detected from a nasopharyngeal swab and feces, respectively. The clinical symptoms accompanied a marked decline in the serum immunoglobulin G level with progressive eosinophilia. Her symptoms disappeared by 8 weeks after onset. She was diagnosed as having masticator myopathy, which has rarely been reported in humans. The present case suggests that masticator myopathy is associated with coxsackie or echo virus infection.

Myositis in children

Idiopathic inflammatory myositis in children includes multiple disease entities, but is primarily made up of juvenile dermatomyositis and, to a lesser degree, juvenile polymyositis. Much new information has been published in the last few years about these diseases, including the epidemiology, pathogenesis, clinical diagnosis, and outcomes and treatment. This includes information on onset of symptoms, potential inciting agents, and regional differences. Exciting data have emerged in our understanding of the immune response gene associations and the description of chimerism in children with these disorders. Finally, new advances in clinical evaluations and outcomes have been described as well as new treatment protocols to provide a more effective therapy with less toxicity. Continued investigation is needed to further understand these diseases, but great strides are being made in our understanding and ability to care for children with idiopathic inflammatory myositis.

Classification and treatment of the juvenile idiopathic inflammatory myopathies

This article reviews the current status of the classification and treatment of the juvenile idiopathic inflammatory myopathies. The intent of classification is to define homogeneous groups that share similar clinical features, disease courses, and responses to therapy. The classification scheme proposed includes clinicopathologic subsets, serologic subjects based on the presence of myositis-specific and myositis-associated autoantibodies, and environmental triggers of myositis. Juvenile dermatomyositis is the most common and widely recognized of these disorders. The second part reviews the history of treatment of juvenile dermatomyositis and discusses agents to consider for patients with refractory disease, unacceptable steroid toxicity, or poor prognostic factors.

Search for picornaviruses at onset of inflammatory myopathy

Picornaviruses may not play a role as persistent agents in the inflammatory myopathies, but it is still thought likely that they may act as triggers of an autoimmune process. Forty one muscle biopsy specimens, taken from three weeks to six months (mean four months) after onset, were examined using three different picornaviral primers and PCR. Moderate to severe disease activity was evident in all specimens. The results were compared with those of 18 biopsy specimens examined later in the disease course, and with specimens from 27 patients with non-inflammatory myopathies. All results were negative. Thus, even as early as three weeks after clinical disease appears, picornaviruses are not detectable in these disorders.