Necrotizing Fasciitis versus Pyomyositis: Discrimination with Using MR Imaging

OBJECTIVE: We wanted to evaluate the MR findings for differentiating between necrotizing fasciitis (NF) and pyomyositis (PM). MATERIALS AND METHODS: The MR images of 19 patients with surgically confirmed NF (n = 11) and pathologically confirmed PM (n = 8) were retrospectively reviewed with regard to the presence or absence of any MRI finding criteria that could differentiate between them. RESULTS: The patients with NF had a significantly greater prevalence of the following MR findings (p < 0.05): a peripheral band-like hyperintense signal in muscles on fat-suppressed T2-weighted images (73% of the patients with NF vs. 0% of the patients with PM), peripheral band-like contrast enhancement (CE) of muscles (82% vs. 0%, respectively) and thin smooth enhancement of the deep fascia (82% vs. 13%, respectively). The patients with PM had a significantly greater prevalence of the following MRI findings (p < 0.05): a diffuse hyperintense signal in muscles on fat-suppressed T2-weighted images (27% of the patients with NF vs. 100% in the patients with PM), diffuse CE of muscles (18% vs. 100%, respectively), thick irregular enhancement of the deep fascia (0% vs. 75%, respectively) and intramuscular abscess (0% vs. 88%, respectively). For all patients with NF and PM, the superficial fascia and muscle showed hyperintense signals on T2-weighted images and CE was seen on fat-suppressed CE T1-weighted images. The subcutaneous tissue and deep fascia showed hyperintense signals on T2-weighted images and CE was seen in all the patients with NF and in seven (88%) of the eight patients with PM, respectively. CONCLUSION: MR imaging is helpful for differentiating between NF and PM.

Síndromes dolorosas em diabéticos por comprometimento de musculatura esquelética / Painful syndromes in diabetic patients due to skeletal muscle injuries / Painful syndromes in diabetic patients due to skeletal muscle injuries

Em diabéticos, síndromes dolorosas devidas o comprometimento do músculo esquelético sem neuropatia são complicações raras. Neste relato são apresentados dois casos: Caso 1 (piomiosite em panturrilhas) e Caso 2 (infarto muscular em coxa), sendo comentadas as características clínicas e os procedimentos diagnósticos. É necessário um alto índice de suspeita, uma vez que o tratamento de ambas difere significativamente. Além disso, o diagnóstico pode ser inicialmente confundido com tromboflebite, rabdomiólise ou neoplasia, retardando o tratamento correto. O atraso no tratamento da piomiosite com antibiótico e em alguns casos com cirurgia, pode evoluir para infecção sistêmica e até óbito, enquanto o infarto muscular requer apenas repouso e analgesia. Exames de imagem e de laboratório são úteis no diagnóstico diferencial, porém pode haver superposição dos achados. É enfatizada a importância de incluir estas doenças no diagnóstico diferencial de síndromes dolorosas do membro inferior em diabéticos.

Progressive painful syndromes due to skeletal muscle injuries rather than diabetic neuropathy are unusual complications of diabetes mellitus (DM). Two clinical cases are presented: Case 1 (pyomyositis: leg location) and Case 2 (muscle infarction: thigh location). Discussion on how to proceed the diagnosis based on clinical features are included as it is critical for early and proper treatment since approaches highly differ in the two situations. These complications can mimic thrombophlebitis, rabdomyolises or a neoplasm, therefore the diagnosis of a diabetes-related disorder may be overlooked. If pyomyositis is not correctly treated with antibiotics and in some cases with surgery, systemic infection and even death may occur, whereas muscle infarction only requires rest and analgesia. Image and laboratorial investigations can be of help to differentiate these syndromes, although some findings can overlap. Thus, the present report emphasizes the importance to include these diseases when limb painful syndromes are to be investigated in a diabetic patient.

Piomiositis tropical: experiencia en un servicio universitario de padiatría / Tropical pyomyositis: experience at on university pediatric departmment

La piomiositis tropical es una infección primaria de uno o más músculos esqueléticos, que puede evolucionar rápidamente y llevar la paciente a un estado de sepsis o a la muerte. Revisamos las historias clínicas de 9 niños con una edad promedio de 7 años hospitalizados en el servicio, entre los años 1996-2000 con diagnósticos de piomiositis tropical, las manifestaciones clínicas principales fueron fiebre alta mayor de 39°C, signos locales de inflamación e impotencia funcional. En 5 de ellos hubo compromiso de varios grupos musculares y en todos hubo afectación del cuadriceps crural (muslo). Se aisló staphylococcus aureus en 2 hemocultivos y en 7 muestras del material purulento obtenido mediante punción percutánea con aguja n°18. El ultrasonido fue diagnóstico en todos los casos revelando imágenes de licuefacción y formación de abscesos intramusculares. Todos los pacientes recibieron antibioticoterapia combinada parenteral con 2 drogas sinérgicas, cefazolina y gentamicina, al inicio del tratamiento. Una vez estabilizado el cuadro clínico, se pasó a la administración oral con cefalexina y asociada o no a rifampicina. Tres pacientes necesitaron drenaje quirúrgico abierto. Se recomendó el diagnóstico oportuno y el manejo agresivo de esta enfermedad, a fin de evitar las metástasis piogénicas desde el músculo al resto de la economía.