Donita B. Sullivan

Childhood dermatomyositis: Factors predicting functional outcome and development of dystrophic calcification

The medical records of 47 children with dermatomyositis who were seen in the pediatric rheumatology clinic at the University of Michigan between 1964 and 1982 were reviewed. Although most children with dermatomyositis have a good prognosis, the best predictor of both good functional recovery and minimal calcinosis is early treatment after the onset of symptoms, using high doses of prednisone for an adequate length of time. Of the children given such treatment, 78% had good functional outcomes, and disabling calcinosis was seen in 20% or less. Children given treatment late in the course of disease and with low doses of steroids are more likely to be functionally limited and have a greater amount of dystrophic calcium salt deposition. In our study, only 33% of patients given such treatment had a mild disease course with good functional outcome. We have identified a subgroup of children with dermatomyositis who appear to do poorly despite optimal therapeutic regimens. These patients are distinguished by a severe disease course responding minimally to corticosteroid therapy and manifested by persistent muscle weakness, elevations of muscle enzyme activity, and severe generalized cutaneous vasculitis. These children are at high risk for the development of exoskeleton-like calcification; consideration should be given to combined immunosuppressive therapy early in the course of disease.

Prognosis in childhood dermatomyositis

The insidious onset of progressive muscle weakness in a child may go unnoticed until fever, rash, or muscle pain prompts the family to seek medical attention. Although the diagnosis of dermatomyositis may be suspected, and muscle biopsy and electromyography are later confirmatory, the single most useful method of assessment is determination of the concentration of the serum muscle enzymes. Prompt treatment with corticosteroids has undoubtedly contributed to the currently improved prognosis. Of the 18 children reported in this study, one died of trauma, and all of the remaining individuals have been maintained in functional independence.

Clinical correlates of antinuclear antibodies in juvenile rheumatoid arthritis

The presence of antinuclear antibodies (ANA) was determined by an immunofluorescent technique in 200 children with juvenile rheumatoid arthritis and was compared to that in 80 children with other connective tissue diseases, 164 children with nonconnective tissue diseases, and 90 normal children. The low frequency of positive tests in normal children (3 per cent) and in nonconnective tissue diseases (1 per cent) compared with the high seropositivity in children with systemic lupus erythematosus (100 per cent), polyarteritis (75 per cent), and juvenile rheumatoid arthritis (38.5 per cent) demonstrates that the method used to detect ANA is both sensitive and selective. In juvenile rheumatoid arthritis, ANA were found significantly more frequently in girls, in patients with early onset of disease or whose present age was young, and in those with polyarticular disease or with monarticular disease and iridocyclitis.

Magnetic resonance imaging appearance of the muscles in childhood dermatomyositis

Documentation of muscle involvement in a child thought to have dermatomyositis may require the performance of invasive procedures such as electromyography and/or muscle biopsy. We describe four patients with dermatomyositis in whom magnetic resonance imaging (MRI) demonstrated the muscle involvement. The involved muscles had increased signal intensity on the T2-weighted images (SE 2500/80) and normal appearance on the T1-weighted images (SE 600/20). The involvement of the muscles was not uniform. There was good correlation between the distribution of muscle involvement by MRI and functional testing. Follow-up MRI scans in patients with favorable outcome demonstrated that the affected muscles had returned to normal signal intensity. Although the MRI findings are not specific, in the proper clinical context they may be helpful in establishing the diagnosis of dermatomyositis. MRI may also be used in establishing an appropriate muscle biopsy site. In addition, MRI may be used for monitoring the progress of the disease.

A syndrome of childhood polyarteritis

In this report the clinical, laboratory, and histopathologic findings of nine children with polyarteritis are reviewed. All have had evidence of systemic involvement. Eight presented with fever, calf pain, erythematous painful nodules, and elevation of the acute-phase reactants. All were treated with prednisone at a dosage of 2 mg/kg/day. All of the children are alive but have had relapses at least once during the course of tapering the dosage of corticosteroids. Serious complications of disease have included myocardial infarction, hypertension, and impaired renal function.

Abnormalities in the Distribution of Serum Immunoglobulin Concentrations in Juvenile Rheumatoid Arthritis

Concentrations of serum IgG. IgA, and IgM were determined in 200 patients with juvenile rheumatoid arthritis. The relative frequency distribution of IgG and IgM approached that of a log-normal curve; however, there was marked skewing of the distribution of the serum concentrations of IgA. The prevalence of selective IgA deficiency was 4%. In order to permit further intragroup comparisons, the serum immunoglobulin concentrations were standardized by comparison to a sex-age matched control group. By this process it was found that there was concordance of the serum levels of IgG with IgA, and IgG with IgM. The standardized concentrations of IgA and IgM were less in females than males. The aberration in distribution of serum IgA concentrations found in this study, and the relative inability of females to respond to their disease by increasing specific serum immunoglobulin levels, add further data supporting the concept of immunodeficiency in the pathogenesis of juvenile rheumatoid arthritis.

Renal papillary necrosis in juvenile rheumatoid arthritis

Three patients who developed renal papillary necrosis while receiving long-term, high-dose aspirin therapy for juvenile rheumatoid arthritis are presented. It appears that aspirin alone or aspirin in combination with other drugs is the causative agent. The incidence and biologic significance of renal papillary necrosis are insufficient to alter the use of aspirin as the drug of choice in management of JRA. It is recommended that all children with JRA be encouraged to drink ample fluids and be followed with periodic urinalysis and blood pressure measurements. Those children who develop hematuria or hypertension should be evaluated by excretory urography.

Scleroderma in the child

Twelve children with scleroderma are presented. All had characteristic cutaneous abnormalities and manifestations of visceral involvement. Raynauds phenomenon and joint symptoms frequently prompted medical consultation. The presence of visceral disease may be overlooked unless specific diagnostic procedures such as pulmonary function testing, gastrointestinal radiographs, esophageal motility studies, and plethysmography are routinely employed since the patients may be asymptomatic.

Retinopathy in juvenile dermatomyositis

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Diagnostic significance of antibody to native deoxyribonucleic acid in children with juvenile rheumatoid arthritis and other connective tissue diseases

Sera of children with juvenile rheumatoid arthritis and other connective tissue diseases were tested for antibodies to native DNA by a radiolabeled-binding assay. Normal values were obtained in 130 children with JRA, including 28 with uveitis and 14 with selective IgA deficiency. Normal values were also found in sera from children with dermatomyositis, scleroderma, polyarteritis, ankylosing spondylitis, and a variety of other nonconnective tissue diseases. The only sera with elevated DNA-binding assays were from children with systemic lupus erythematosus. On the basis of these data, increased levels of antibodies to native DNA distinguished patients with active SLE from children with JRA.