title: North American contact dermatitis group patch test results: 2011-2012.
abstract: BACKGROUND
  Patch testing is an important diagnostic tool for assessment of allergic contact dermatitis (ACD).
  
  
  OBJECTIVE
  This study documents the North American Contact Dermatitis Group (NACDG) patch-testing results from January 1, 2011, to December 31, 2012.
  
  
  METHODS
  At 12 centers in North America, patients were tested in a standardized manner with a series of 70 allergens. Data were manually verified and entered into a central database. Descriptive frequencies were calculated, and trends analyzed using χ statistics.
  
  
  RESULTS
  Four thousand two hundred thirty-eight patients were tested; of these, 2705 patients (63.8%) had at least 1 positive reaction, and 2029 (48.0%) were ultimately determined to have a primary diagnosis of ACD. Four hundred eight patients (9.6%) had occupationally related skin disease. There were 7532 positive allergic reactions. As compared with previous reporting periods (2009-2010 and 2000-2010), positive reaction rates statistically increased for 6 allergens: methylchloroisothiazolinone/methylisothiazolinone (5.0%; risk ratios [RRs]: 2.01 [1.60-2.52], 1.87 [1.61-2.18]), lanolin alcohol (4.6%; RRs 1.83 [1.45-2.30], 2.10 [1.79-2.47]), cinnamic aldehyde (3.9%; 1.69 [1.32-2.15], 1.53 [1.28-1.82]), glutaral (1.5%; 1.67 [1.13-2.48], 1.31 [1.00-1.71]), paraben mix (1.4%; 1.77 [1.16-2.69], 1.44 [1.09-1.92]), and fragrance mix I (12.1%; RRs 1.42 [1.25-1.61], 1.24 [1.14-1.36]). Compared with the previous decade, positivity rates for all formaldehyde-releasing preservatives significantly decreased (formaldehyde 6.6%; RR, 0.82 [0.73, 0.93]; quaternium-15 6.4% RR 0.75 [0.66, 0.85]; diazolidinyl urea 2.1%; RR, 0.67 [0.54, 0.84]; imidazolidinyl urea 1.6%, 0.60 [0.47, 0.77]; bronopol 1.6%; RR, 0.60 [0.46, 0.77]; DMDM hydantoin 1.6%; RR, 0.59 [0.54, 0.84]). Approximately a quarter of patients had at least 1 relevant allergic reaction to a non-NACDG allergen. In addition, approximately one-fourth to one-third of reactions detected by NACDG allergens would have been hypothetically missed by T.R.U.E. TEST (SmartPractice Denmark, Hillerød, Denmark).
  
  
  CONCLUSIONS
  These data document the beginning of the epidemic of sensitivity to methylisothiazolinones in North America, which has been well documented in Europe. Patch testing with allergens beyond a standard screening tray is necessary for complete evaluation of occupational and nonoccupational ACD.
authors.affiliation: From the University of Minnesota and the Minneapolis VAMC; University of California, San Francisco; Cleveland Clinic, Ohio; McGill University Health Centre, Montreal; University of Toronto, Canada; Ohio State University, Columbus; Associates in Dermatology, Fort Myers, Fla; Group Health Associates, Cincinnati, Ohio; Dartmouth Medical Center, Lebanon, NH; St. Luke's Roosevelt Hospital Center, New York, NY; Dermatology Specialists, Louisville, KY; Pennsylvania State University Hershey; University of Ottawa, Canada; Oregon Health Sciences University, Portland; and Columbia University Medical Center, New York, NY.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Warshaw
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
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: Donald V
authors.initials: DV
authors.lastname: Belsito
mesh_terms: D000171:Acrolein / Q000009:adverse effects / Q000031:analogs & derivatives; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D009783:Dermatitis, Occupational / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005557:Formaldehyde / Q000009:adverse effects; D005976:Glutaral / Q000009:adverse effects; D006801:Humans; D006827:Hydantoins / Q000009:adverse effects; D007809:Lanolin / Q000009:adverse effects / Q000031:analogs & derivatives; D008297:Male; D008709:Methenamine / Q000009:adverse effects / Q000031:analogs & derivatives; D008875:Middle Aged; D009656:North America / Q000453:epidemiology; D010226:Parabens / Q000009:adverse effects; D010328:Patch Tests; D010476:Perfume / Q000009:adverse effects; D015995:Prevalence; D011409:Propylene Glycols / Q000009:adverse effects; D013844:Thiazoles / Q000009:adverse effects; D014508:Urea / Q000009:adverse effects / Q000031:analogs & derivatives; D055815:Young Adult
chemical_list: D000485:Allergens; D006827:Hydantoins; D010226:Parabens; D010476:Perfume; D011409:Propylene Glycols; D013844:Thiazoles; D005557:Formaldehyde; C028745:isopropyl lanolin; C006827:bronopol; D000171:Acrolein; D007809:Lanolin; D014508:Urea; C056057:1,3-dimethylol-5,5-dimethylhydantoin; C011421:5-chloro-2-methyl-4-isothiazolin-3-one; C018375:quaternium-15; C044982:diazolidinylurea; D008709:Methenamine; C006048:imidazolidinyl urea; C012843:cinnamaldehyde; D005976:Glutaral