title: Obturator externus abscess in a 9-year-old child: A case report and literature review.
abstract: BACKGROUND
  Obturator pyomyositis is a rare condition in children. Diagnosis is often delayed because of its rarity, and the vagaries of its presentation cause it to be easily be missed. Physicians should therefore familiarize themselves with this condition and consider it as a possible differential diagnosis in patients presenting with an acutely painful hip. Inflammatory syndrome is also frequent among sufferers and the MRI is a very sensitive diagnostic tool for obturator pyomyositis. Additionally, joint fluid aspirations and blood cultures are also useful in identifying the pathogen. The appropriate antibiotic therapy provides a rapid regression of symptoms during the early stage of pyomyositis. In cases of MRI-confirmed abscess, surgical treatment is indicated.
  
  
  METHODS
  Our report focuses on a case of obturator pyomyositis in a 9-year-old boy. The child was febrile for 5 days and could only manage to walk a few steps. His hip range of motion was restricted in all directions. In addition, the patient had presented pain and swelling of his right elbow for a day, with a restriction of motion in the joint. There was a clear inflammatory syndrome. A diagnosis of hip and elbow septic arthritis was suspected, and the child underwent joint aspiration of the both cited joints. The aspiration of the elbow returned pus. Conversely, no effusion was found in the hip aspiration. The administration of empiric intravenous antibiotherapy was started.
  
  
  METHODS
  An MRI revealed an osteomyelitis of the ischio-pubic area associated with a subperiosteal abscess.
  
  
  METHODS
  Subsequently, 3 days after elbow arthrotomy, a surgical treatment was performed on the patient's right hip in order to evacuate the subperiosteal abscess and muscular collection because of the persistence of the patient's symptoms and inflammatory syndrome despite susceptible intravenous antibiotics. Postsurgery the patient showed steady improvement.
  
  
  CONCLUSIONS
  Such cases demonstrate how diagnosis can be difficult because pelvic pyomyositis is often mistaken for more common pathologies such as septic arthritis, osteomyelitis, or appendicitis. This may delay the diagnosis or refer misdiagnosis. We discuss this rare infection in light of the literature with particular reference to its incidence, clinical features, bacteriological etiology, biological, and radiological presentation, and above all, its treatment.
authors.affiliation: Pediatric Orthopedics and Traumatology Unit, Lausanne University Hospital, Lausanne Pediatric Orthopedic Service, University Hospitals of Geneva, Geneva Unit of Paediatric Infectious Diseases, Department of Paediatrics, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Charlotte
authors.initials: C
authors.lastname: de Bodman
authors.forename: Dimitri
authors.initials: D
authors.lastname: Ceroni
authors.forename: Justine
authors.initials: J
authors.lastname: Dufour
authors.forename: Pierre-Alex
authors.initials: PA
authors.lastname: Crisinel
authors.forename: Aline
authors.initials: A
authors.lastname: Bregou-Bourgeois
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Zambelli
mesh_terms: D002648:Child; D006801:Humans; D008297:Male; D010019:Osteomyelitis / Q000175:diagnosis* / Q000628:therapy; D052880:Pyomyositis / Q000175:diagnosis* / Q000628:therapy