title: Low sensitivity of needle aspiration cultures in patients with cellulitis/erysipelas.
abstract: OBJECTIVE
  Cellulitis is normally treated without knowledge of the responsible pathogen. Blood cultures are positive in about 2-4 %, and superficial swabs are of no value. Needle aspiration has been proposed with identifying the likely pathogen in up to 29 %, but these studies are of older date and the technique is not widely used.
  
  
  METHODS
  We prospectively evaluated the sensitivity of needle aspiration cultures in all patients with erysipelas/cellulitis. Diagnosis was made clinically by the treating physician. Needle aspiration was done with a 1 ml syringe and a 26G needle. The needle was removed and the syringe brought to the microbiological laboratory and analysed according to standard procedures.
  
  
  RESULTS
  95 Patients were seen during a period of 22 month. 4 Patients were excluded, as diagnosis was not confirmed. Cellulitis was present in 10/91 and erysipelas in 81/91 patients. In the first 25 patients with needle aspiration from the margin, none was positive. In 8/66 (12 %) patients where needle aspiration was done at the site of maximum inflammation, the pathogen was identified. 4/8 Cultures were positive for S. aureus, 2/8 for streptococci and 2/8 for other bacteria. In 11/66 (16.6 %) patients, skin colonisation flora was detected. In the subgroup of patients without prior antibiotic treatment and needle aspiration from the site of maximum inflammation, sensitivity was slightly better 8/55 (14.5 %; 95 % CI 7.5-25.8 %).
  
  
  CONCLUSIONS
  Needle aspiration culture had a low sensitivity for detecting responsible pathogen in patients with cellulitis/erysipelas. No impact in antibiotic treatment could be observed.
authors.affiliation: Medizinische Klinik, Kantonsspital, Baslerstrasse 150, 4600 Olten, CH Switzerland.
authors.forename: Rein Jan
authors.initials: RJ
authors.lastname: Piso
authors.affiliation: Medizinische Klinik, Kantonsspital, Baslerstrasse 150, 4600 Olten, CH Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Pop
authors.affiliation: Medizinische Klinik, Kantonsspital, Baslerstrasse 150, 4600 Olten, CH Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Wieland
authors.affiliation: Medizinische Klinik, Kantonsspital, Baslerstrasse 150, 4600 Olten, CH Switzerland.
authors.forename: I
authors.initials: I
authors.lastname: Griesshammer
authors.affiliation: Medizinische Klinik, Kantonsspital, Baslerstrasse 150, 4600 Olten, CH Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Urfer
authors.affiliation: Bakteriologisches Institut Olten, Kantonsspital, Olten, Switzerland.
authors.forename: U
authors.initials: U
authors.lastname: Schibli
authors.affiliation: Division of Internal Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Bassetti