The clinical characteristics, response to therapy, and long-term prognosis in 13 children (1.5 to 16 years of age) with chronic inflammatory demyelinating polyneuropathy (CIDP) were reviewed from records of patients seen at Washington University Medical Center, St Louis, MO, and the Royal Children’s Hospital, Melbourne, Australia, between 1979 and 1994. Boys were affected more often than girls in a ratio of 1.6:1. Antecedent events noted within one month of onset occurred in 7 children (54%), and included vaccinations (measles-mumps-rubella immunization in 2), intercurrent infections (URI or tonsillitis in 4), and chicken pox in 1. Lower extremity weakness, associated with difficulty in walking, was the most common presenting symptom, found in 85% of children. Motor symptoms predominated, but sensory symptoms were also noted by 85%. Deep tendon reflexes were diminished or absent in all patients. Facial weakness ocurred in 4. CSF protein was elevated (mean, 177mg/dL) in 92%, but cells were not increased. Electrodiagnostic studies showed F-wave abnormalities (92%) and slowing of nerve conduction velocities (77%). Nerve biopsies performed in 4 showed demyelination. Prednisone resulted in initial improvement in all 13 patients. Relapses required continued prednisone in 8, and other therapies, such as immunoglobulin, plasma exchange, or immunosuppressive medications, were added. One group of patients (4) with weakness developing over a short period of 1 to 3 months showed a monophasic course with complete recovery in 3. A second group (9), with slower evolution of symptoms from 3 months to several years, had no complete recoveries and mild to severe residual weakness. 
COMMENT. Childhood onset chronic inflammatory demyelinating polyneuropathy (CIDP) has in general a poor long-term prognosis, the majority showing relapses and having residual weakness. After an initial improvement with prednisone therapy, attempts to withdraw steroids were often unsuccessful and the addition of immunosuppressive medications was rarely of benefit. The few children who recovered completely had an antecedent illness of URI or tonsillitis. Of two patients with CIDP associated with MMR immunization, none recovered and one had severe residual weakness. CIDP is a previously unreported side effect of MMR immunization. Transverse myelitis following MMR vaccine was reviewed in Ped Neur Briefs Sept 1995;9:65.