title: The Association of Race/Ethnicity and Patch Test Results: North American Contact Dermatitis Group, 1998-2006.
abstract: BACKGROUND
  The North American Contact Dermatitis Group patch tests patients with suspected allergic contact dermatitis (ACD) to a broad series of screening allergens and publishes periodic reports. We have previously reported on the association of race and ethnicity with the rates of positive responses to standard patch test allergens. This report extends those observations.
  
  
  OBJECTIVE
  The aim of the study was to report the North American Contact Dermatitis Group patch testing results from January 1, 1998, to December 31, 2006, comparing the frequency of positive reactions between white and black subjects.
  
  
  METHODS
  Standardized patch testing with 45 allergens was used at 13 centers in North America. χ analysis of results in black subjects as compared with whites was examined.
  
  
  RESULTS
  A total of 19,457 patients were tested; 92.9% (17,803) were white and 7.1% (1,360) were black. The final diagnoses of ACD (whites, 45.9%; blacks, 43.6%) and irritant contact dermatitis (13.0%/13.3%) were similar in the 2 groups. The diagnosis of atopic dermatitis was less common in the white patients (8.9%) as compared with the black patients (13.3%). Positive patch test reactions rates were similar for most allergens. However, statistically, blacks reacted more frequently to p-phenylenediamine (7.0% vs 4.4%, P < 0.001), bacitracin (11.6% vs 8.3%, P = 0.0004), as well as specific rubber accelerators mercaptobenzothiazole (2.7% vs 1.8%), thiuram (6.2% vs 4.3%), and mercapto mix (1.9% vs 0.8%, P < 0.001). Whites had an increase in positive reactions to fragrances (12.12% vs 6.77%, P < 0.0001), formaldehyde (9.25% vs 5.45%, P < 0.0001), and some formaldehyde releaser preservatives used in personal care products and textile resins (9.80% vs 6.18%, P < 0.0001).
  
  
  CONCLUSIONS
  There were statistically different rates of positive patch test reactions to specific allergens between black and white patients suspected of having ACD. The etiology of these differences is unclear but probably relates to culturally determined exposure patterns rather than genetic differences.
authors.affiliation: From the Department of Dermatology, Keck School of Medicine of the University of Southern California, Los Angeles.
authors.forename: Vincent Anthony
authors.initials: VA
authors.lastname: Deleo
authors.forename: Andrew
authors.initials: A
authors.lastname: Alexis
authors.forename: Erin M
authors.initials: EM
authors.lastname: Warshaw
authors.forename: Denis
authors.initials: D
authors.lastname: Sasseville
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
authors.forename: Joel
authors.initials: J
authors.lastname: DeKoven
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Zug
authors.forename: Donald V
authors.initials: DV
authors.lastname: Belsito
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Fowler
authors.forename: James G
authors.initials: JG
authors.lastname: Marks
authors.forename: C G Toby
authors.initials: CG
authors.lastname: Mathias
authors.forename: Melanie D
authors.initials: MD
authors.lastname: Pratt
authors.forename: Robert L
authors.initials: RL
authors.lastname: Rietschel
authors.forename: Frances J
authors.initials: FJ
authors.lastname: Storrs
authors.forename: James S
authors.initials: JS
authors.lastname: Taylor
authors.forename: Matthew
authors.initials: M
authors.lastname: Zirwas
mesh_terms: D001741:Black or African American; D000485:Allergens / Q000009:adverse effects; D044383:Black People; D002170:Canada; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000208:ethnology* / Q000209:etiology; D003876:Dermatitis, Atopic / Q000175:diagnosis / Q000208:ethnology*; D017453:Dermatitis, Irritant / Q000175:diagnosis / Q000208:ethnology* / Q000209:etiology; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D010328:Patch Tests; D014481:United States; D044465:White People
chemical_list: D000485:Allergens