title: Shoe allergens: retrospective analysis of cross-sectional data from the north american contact dermatitis group, 2001-2004.
abstract: BACKGROUND
  Chemicals used in leather tanning, rubber processing, and/or adhesives are the most often-cited culprits in footwear dermatitis. Patch testing patients with suspected shoe dermatitis is essential for diagnosis and management.
  
  
  OBJECTIVE
  The four goals for this study were to (1) determine the frequency of allergens associated with a shoe source in North American Contact Dermatitis Group (NACDG) patients with footwear allergic contact dermatitis; (2) compare these results to allergen frequencies from other published studies; (3) quantify the number of shoe-related reactions that were not identified with the NACDG standard series; and (4) identify relevant allergens not included on the NACDG standard series, based on data from other published studies.
  
  
  METHODS
  The NACDG patch-tested 10,061 patients between 2001 and 2004. Data were retrospectively analyzed by (1) allergen source coded as "shoe," (2) site of dermatitis as "feet," and (3) diagnosis of "allergic contact dermatitis."
  
  
  RESULTS
  Among the 109 NACDG patients with allergic contact dermatitis (ACD) of the foot and a shoe source of allergens, p-tertiary butylphenol formaldehyde resin, an adhesive, was the most common allergen, accounting for 24.7% of positive patch-test results, followed by potassium dichromate (17.5%) and carba mix (11.7%). When the data were examined according to groups of allergens, rubber chemicals (40.4%) were the most frequent allergens, followed by adhesives (32.5%), and leather components (20.1%). When data from published studies were pooled, potassium dichromate (31.5%) was the most frequent allergen, followed by p-tertiary butylphenol formaldehyde resin (17.1%) and cobalt chloride (12.9%). NACDG patients were statistically more likely to have positive patch-test reactions to p-tertiary butylphenol formaldehyde resin and statistically less likely to have a positive patch-test reaction to potassium dichromate than patients represented in pooled data from past studies. Nineteen (17.4%) of the 109 NACDG patients with ACD of the foot and a shoe source of allergens were identified as having a shoe source of a relevant allergen not included in the NACDG standard series.
  
  
  CONCLUSIONS
  In NACDG patients, the most common individual shoe allergen was p-tertiary butylphenol formaldehyde resin. As a group, rubber chemicals were most common, a finding consistent with those of other studies.
authors.affiliation: Veterans Affairs Medical Center, Minneapolis, MN, USA.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Warshaw
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Schram
authors.forename: Donald V
authors.initials: DV
authors.lastname: Belsito
authors.forename: Vincent A
authors.initials: VA
authors.lastname: DeLeo
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Fowler
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
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: 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: Kathryn A
authors.initials: KA
authors.lastname: Zug
mesh_terms: D000269:Adhesives / Q000032:analysis* / Q000633:toxicity; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens / Q000032:analysis* / Q000633:toxicity; D002648:Child; D004396:Coloring Agents / Q000032:analysis / Q000633:toxicity; D003430:Cross-Sectional Studies; D003877:Dermatitis, Contact / Q000453:epidemiology* / Q000209:etiology; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D062665:Epidemiological Monitoring; D005260:Female; D005533:Foot Dermatoses / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009656:North America / Q000453:epidemiology; D010328:Patch Tests; D012117:Resins, Synthetic / Q000032:analysis / Q000633:toxicity; D012189:Retrospective Studies; D012408:Rubber / Q000032:analysis* / Q000633:toxicity; D012775:Shoes / Q000706:statistics & numerical data*
chemical_list: D000269:Adhesives; D000485:Allergens; D004396:Coloring Agents; D012117:Resins, Synthetic; C014273:p-tert-butylphenolformaldehyde resin; D012408:Rubber