title: Sweat test in patients with glucose-6-phosphate-1-dehydrogenase deficiency.
abstract: BACKGROUND
  A false-positive sweat test in patients with deficiency of glucose-6-phosphate-1-dehydrogenase (EC 1.1.1.49; G6PD) is repeatedly reported.
  
  
  METHODS
  Sweat chloride or conductivity was measured in 11 patients with G6PD deficiency.
  
  
  RESULTS
  Mean (SD) chloride level (n = 8, median age 9.2 years, range 1.9-48.5) was 18.8 (9.6 mmol/l) and, mean (SD) sodium level was 26.0 (10.0 mmol/l), respectively, and mean (SD) conductivity (n = 3, median age 6.6 years, range 1.9-40.5) was 34.3 (6.5 mmol/l).
  
  
  CONCLUSIONS
  In sweat of 11 patients with G6PD deficiency we did not find any abnormality. The reason for alleged false-positive sweat test in patients with G6PD deficiency is not known and we were unable to identify any original reference. It appears that tables of putative false-positive sweat tests in several disease states have been directly "copied and pasted" from one paper or textbook to another without verifying the original literature, a phenomenon one can call "chain citation".
authors.affiliation: Department of Paediatrics, University of Berne, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Casaulta
authors.forename: A
authors.initials: A
authors.lastname: Stirnimann
authors.forename: M H
authors.initials: MH
authors.lastname: Schoeni
authors.forename: J
authors.initials: J
authors.lastname: Barben
mesh_terms: D000328:Adult; D002648:Child; D002675:Child, Preschool; D002712:Chlorides / Q000032:analysis; D003550:Cystic Fibrosis / Q000175:diagnosis; D003937:Diagnosis, Differential; D004553:Electric Conductivity; D005189:False Positive Reactions; D005260:Female; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012964:Sodium / Q000032:analysis; D013542:Sweat / Q000737:chemistry*
chemical_list: D002712:Chlorides; D012964:Sodium