OSTEOMYELITIS IN HOSPITALIZED CHILDREN WITH CHICKENPOX - IMAGING FINDINGS IN 4 CASES

OBJECTIVE. The most common complications of chickenpox are skin and so ft-tissue infections. Pneumonia and CNS involvement occur less often, and skeletal complications are considered rare. The purpose of this st udy was to evaluate the imaging findings of osteomyelitis in children after chickenpox. MATERIALS AND METHODS. We retrospectively reviewed t he records of children admitted to our institution because of chickenp ox and analyzed the imaging findings in those who had skeletal involve ment. Ninety-seven patients were admitted between January 1991 and Jan uary 1993 because of chickenpox or a complication thereof. Four previo usly healthy patients, three boys and one girl, between 1 and 6 years old had osteomyelitis. Staphylococcus aureus was isolated from bone in one patient, and group A beta-hemolytic streptococcus was isolated fr om blood cultures in another. No organism was grown in the other two; necrotic bone was recovered from one lesion and the other healed with periosteal formation of new bone typical of osteomyelitis. All patient s were treated with IV antibiotics, and their recoveries were uncompli cated. RESULTS. Conventional radiographs showed loss of fat planes in three patients and destruction of bone in two. Bone scintigraphy showe d increased uptake of radionuclide in early and late phases in three p atients. Uptake in one case was extensive, with a central area of rela tively little uptake corresponding to a subperiosteal fluid collection . CT in two and MR imaging in one showed subperiosteal fluid collectio ns surrounding the involved bones in association with bone and marrow changes. CONCLUSION. Osteomyelitis was the fourth most common complica tion of chickenpox in our series. The appearances on conventional radi ographs and scintigrams are indistinguishable from those of typical ba cterial osteomyelitis. However, CT and MR imaging showed subperiosteal fluid collections in three of four patients, an appearance only occas ionally seen with typical osteomyelitis.