title: Patch-test results of the North American Contact Dermatitis Group 2005-2006.
abstract: BACKGROUND
  The North American Contact Dermatitis Group (NACDG) tests patients who have suspected allergic contact dermatitis with a broad series of screening allergens, and publishes periodic reports of its data.
  
  
  OBJECTIVE
  To report the NACDG patch-test results from January 1, 2005, to December 31, 2006, and to compare results to pooled test data from the previous 10 years.
  
  
  METHODS
  Standardized patch testing with 65 allergens was used at 13 centers in North America. Chi-square statistics were utilized for comparisons with previous NACDG data.
  
  
  RESULTS
  NACDG patch-tested 4,454 patients; 12.3% (557) had an occupation-related skin condition, and 65.3% (2,907) had at least one allergic patch-test reaction. The 15 most frequently positive allergens were nickel sulfate (19.0%), Myroxilon pereirae (balsam of Peru, 11.9%), fragrance mix I (11.5%), quaternium-15 (10.3%), neomycin (10.0%), bacitracin (9.2%), formaldehyde (9.0%), cobalt chloride (8.4%), methyldibromoglutaronitrile/phenoxyethanol (5.8%), p-phenylenediamine (5.0%), potassium dichromate (4.8%), carba mix (3.9%), thiuram mix (3.9%), diazolidinylurea (3.7%), and 2-bromo-2-nitropropane-1,3-diol (3.4%). As compared to the 1994-2004 data, there were significant increases in rates of positivity to nickel, quaternium-15, potassium dichromate, lidocaine, and tea tree oil. Of patch-tested patients, 22.9% (1,019) had a relevant positive reaction to a supplementary allergen; 4.9% (219) had an occupationally relevant positive reaction to a supplementary allergen.
  
  
  CONCLUSIONS
  Nickel has been the most frequently positive allergen detected by the NACDG; rates significantly increased in the current study period and most reactions were clinically relevant. Other common allergens were topical antibiotics, preservatives, fragrance mix I and paraphenylenediamine. Testing with an expanded allergen series and supplementary allergens enhances detection of relevant positive allergens.
authors.affiliation: Dartmouth-Hitchcock Medical Center & Dartmouth Medical School, Lebanon, NH, USA.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Zug
authors.forename: Erin M
authors.initials: EM
authors.lastname: Warshaw
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Fowler
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
authors.forename: Donald L
authors.initials: DL
authors.lastname: Belsito
authors.forename: Melanie D
authors.initials: MD
authors.lastname: Pratt
authors.forename: Denis
authors.initials: D
authors.lastname: Sasseville
authors.forename: Frances J
authors.initials: FJ
authors.lastname: Storrs
authors.forename: James S
authors.initials: JS
authors.lastname: Taylor
authors.forename: C G Toby
authors.initials: CG
authors.lastname: Mathias
authors.forename: Vincent A
authors.initials: VA
authors.lastname: Deleo
authors.forename: Robert L
authors.initials: RL
authors.lastname: Rietschel
authors.forename: James
authors.initials: J
authors.lastname: Marks
mesh_terms: D000485:Allergens / Q000009:adverse effects*; D004396:Coloring Agents / Q000009:adverse effects*; D003358:Cosmetics / Q000009:adverse effects*; D019992:Databases as Topic; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D009532:Nickel / Q000009:adverse effects; D009656:North America / Q000453:epidemiology; D010328:Patch Tests / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D011310:Preservatives, Pharmaceutical / Q000009:adverse effects*; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods
chemical_list: D000485:Allergens; D004396:Coloring Agents; D003358:Cosmetics; D011310:Preservatives, Pharmaceutical; D009532:Nickel