The prevention of infectious diseases by immunization is the most familiar application of preventive pediatrics,1 and is now a routine practice during the first years of life. Currently recommended procedures for active immunization are widely accepted and are carried out with almost complete freedom from complications. However, complications can occur, and this report describes an unusual problem developing from a vaccination with "measles, mumps, and rubella virus vaccine, live."
Report of a Case.—A 19-month-old child was seen approximately 3½ months after receiving a routine measles, mumps, and rubella vaccination in the right buttock. She had been well prior to the vaccination, and until approximately two weeks afterwards, at which time a small defect involving the subcutaneous fatty tissue was noticed in the right buttock at the vaccination site. This progressively increased in size; at the time of initial evaluation, there was a 32 × 18-mm atrophic-like defect, with