Juvenile myasthenia gravis.

Juvenile myasthenia gravis shares a similar pathophysiologic origin with adult myasthenia gravis, but there are important differences, mostly relating to epidemiology, presentation, and therapeutic decision making. Gender ratios and the proportion of seropositive patients differ in the pre- and postpubertal age groups. The diagnostic evaluation is similar to that in adults, although special techniques are sometimes necessary to perform single-fiber electromyography in younger patients. Therapeutic decisions in affected children and adolescents are complicated by the greater long-term consequences of using steroids, and thus other interventions, such as intravenous immunoglobulin (IVIg) and plasmapheresis, may play a greater therapeutic role in this population than in adults. Steroid-sparing agents may contribute to the management of refractory cases, but they should be used with caution due to the risk of malignancy.