Juvenile Dermatomyositis and the Inflammatory Myopathies

Abstract

The inflammatory myopathies comprise disorders of immune-mediated muscle injury. The histopathology and clinical features help distinguish them. Juvenile dermatomyositis (JDM) is the most common form of myositis in children and adolescents. Children with JDM present with proximal muscle weakness and characteristic rashes. The presentation is similar in children and adults, but JDM is a primary disorder and the adult form often is concerning for a paraneoplastic syndrome. Proximal muscle weakness occurs with dermatomyositis, polymyositis, and immune-mediated necrotizing myopathy, but the latter two conditions have no dermatologic findings or distinct tissue changes which set them apart from dermatomyositis. Inclusion body myositis, also included in the inflammatory myopathies, presents with more distal involvement, and microscopically exhibits identifiable rimmed vacuoles. We review key features of these disorders, focusing in more detail on JDM because it is more often encountered by the child neurologist.

Case Report: Pediatric Malignant Atrophic Papulosis With Small Bowel Perforation and Positivity of Anticardiolipin Antibody

“…In patients with JDM, tissue inflammation is most obvious in the skeletal muscle and skin, presenting symmetric proximal weakness and characteristic lesions. Dermatologic characteristics of JDM comprise the heliotrope rash, Gottron's papules, and nail fold changes (8). In our case, the patient did not have any of these features or muscle weakness.…”

Atrophic facial scarring in a 6‐year‐old girl

“…Important differential diagnoses to consider include bullous lupus erythematosus or dermatitis herpetiformis, as well as muscular dystrophy, endocrine myopathy, or neuromuscular disease; however the latter three would not present with cutaneous findings. In the present case, our diagnosis was guided by the skin lesions observed, the abnormalities detected in the laboratory analysis and the biopsy results 11 …”

“…In the present case, our diagnosis was guided by the skin lesions observed, the abnormalities detected in the laboratory analysis and the biopsy results. 11 Regarding autoantibodies, positive antinuclear antibodies have been detected in 60% of patients the JDM, but they are not disease specific. In children, this association has also been described, notably anti-Mi-2 (associated with good response to treatment), antisynthetase and more recently anti-p155 (detected in 20%-30% of patients with JDM).…”

Dermatomiose Juvenil: Relato De Caso

“…A causa exata da DMJ é desconhecida, mas várias teorias surgiram ao longo dos anos. Por exemplo, estudos apontam um forte componente genético para a doença com marcadores específicos, como o duplo sorotipo HLA-D3 (REED; PACHMAN;OBER, 1991;SWAFFORD;ROACH, 2020).…”

“…As limitações funcionais da DMJ incluem dificuldade para andar, usar escadas ou levantar os braços acima da cabeça (HARRIS-LOVE et al, 2009;SWAFFORD;ROACH, 2020) e a fraqueza muscular pode progredir para os músculos bulbares, levando à disfonia e disfagia, que podem ser percebidas por uma qualidade nasal à voz ou tosse com deglutição (AL-MAYOUF et al, 2017;BELLUTTI ENDERS et al, 2017). Além disso, a fraqueza pode ter uma apresentação aguda ou pode levar de semanas a meses para se desenvolver, dependendo do grau de inflamação.…”