title: North American Contact Dermatitis Group patch test results: 2009 to 2010.
abstract: BACKGROUND
  Patch testing is an important diagnostic tool for determination of substances responsible for allergic contact dermatitis.
  
  
  OBJECTIVE
  This study reports the North American Contact Dermatitis Group (NACDG) patch testing results from January 1, 2009, to December 31, 2010.
  
  
  METHODS
  At 12 centers in North America, patients were tested in a standardized manner with a screening series of 70 allergens. Data were manually verified and entered into a central database. Descriptive frequencies were calculated, and trends were analyzed using χ2 statistics.
  
  
  RESULTS
  A total of 4308 patients were tested. Of these, 2614 (60.7%) had at least 1 positive reaction, and 2284 (46.3%) were ultimately determined to have a primary diagnosis of allergic contact dermatitis. Four hundred twenty-seven (9.9%) patients had occupationally related skin disease. There were 6855 positive allergic reactions. As compared with the previous reporting period (2007-2008), the positive reaction rates statistically decreased for 20 allergens (nickel, neomycin, Myroxylon pereirae, cobalt, formaldehyde, quaternium 15, methydibromoglutaronitrile/phenoxyethanol, methylchlorisothiazolinone/methylisothiazolinone, potassium dichromate, diazolidinyl urea, propolis, dimethylol dimethylhydantoin, 2-bromo-2-nitro-1,3-propanediol, methyl methacrylate, ethyl acrylate, glyceryl thioglycolate, dibucaine, amidoamine, clobetasol, and dimethyloldihydroxyethyleneurea; P < 0.05) and statistically increased for 4 allergens (fragrance mix II, iodopropynyl butylcarbamate, propylene glycol, and benzocaine; P < 0.05). Approximately one quarter of tested patients had at least 1 relevant allergic reaction to a non-NACDG allergen. Hypothetically, approximately one quarter of reactions detected by NACDG allergens would have been missed by TRUE TEST (SmartPractice Denmark, Hillerød, Denmark).
  
  
  CONCLUSIONS
  These results affirm the value of patch testing with many allergens.
authors.affiliation: Department of Dermatology, Minneapolis VA Health Care System and University of Minnesota, Minneapolis, MN, USA. erin.warshaw@med.va.gov
authors.forename: Erin M
authors.initials: EM
authors.lastname: Warshaw
authors.forename: Donald V
authors.initials: DV
authors.lastname: Belsito
authors.forename: James S
authors.initials: JS
authors.lastname: Taylor
authors.forename: Denis
authors.initials: D
authors.lastname: Sasseville
authors.forename: Joel G
authors.initials: JG
authors.lastname: DeKoven
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Zirwas
authors.forename: Anthony F
authors.initials: AF
authors.lastname: Fransway
authors.forename: C G Toby
authors.initials: CG
authors.lastname: Mathias
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Zug
authors.forename: Vincent A
authors.initials: VA
authors.lastname: DeLeo
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Fowler
authors.forename: James G
authors.initials: JG
authors.lastname: Marks
authors.forename: Melanie D
authors.initials: MD
authors.lastname: Pratt
authors.forename: Frances J
authors.initials: FJ
authors.lastname: Storrs
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens; D002648:Child; D002675:Child, Preschool; D003877:Dermatitis, Contact / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009656:North America; D010328:Patch Tests / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D000485:Allergens