title: Occupational contact allergy to monomeric isocyanates.
abstract: BACKGROUND
  The monomeric isocyanates diphenylmethane diisocyanate (MDI), 2,4-toluene diisocyanate (TDI), isophorone diisocyanate (IPDI) and 1,6-hexamethylene diisocyanate (HDI) are used in polyurethane products and sometimes cause contact allergy.
  
  
  OBJECTIVE
  To describe patients with isocyanate contact allergy in an occupational dermatology clinic.
  
  
  METHODS
  Test files were screened for allergic reactions to isocyanates and 4,4'-diaminodiphenylmethane (MDA). Patients with allergic reactions to some of the allergens were analysed for occupation, exposure, concomitant reactions to other allergens, and diagnosis.
  
  
  RESULTS
  Over a period of almost 13 years, 54 patients reacted to isocyanates (9 to IPDI, 12 to MDI, 6 to TDI, and 1 to HDI) or MDA (44 patients). The motor vehicle, electronics and paint industries, and painting and construction work, were among the most significant occupational fields. An in-house polymeric MDI (PMDI) test substance was superior to commercial MDI preparations. About half of the occupational cases related to MDI products were diagnosed by testing MDA. The most prominent cause of IPDI allergy comprised polyurethane paint hardeners. Some of the IPDI reactions could be explained by cross-allergy to isophoronediamine in epoxy products. Specific exposure to MDA was difficult to trace.
  
  
  CONCLUSIONS
  MDA and PMDI test substances were significant in the diagnosis of MDI contact allergy.
authors.affiliation: Control of Hypersensitivity Diseases, Finnish Institute of Occupational Health, 00250 Helsinki, Finland. kristiina.aalto-korte@ttl.fi
authors.forename: Kristiina
authors.initials: K
authors.lastname: Aalto-Korte
authors.forename: Katri
authors.initials: K
authors.lastname: Suuronen
authors.forename: Outi
authors.initials: O
authors.lastname: Kuuliala
authors.forename: Maj-Len
authors.initials: ML
authors.lastname: Henriks-Eckerman
authors.forename: Riitta
authors.initials: R
authors.lastname: Jolanki
mesh_terms: D000485:Allergens / Q000009:adverse effects*; D000814:Aniline Compounds / Q000009:adverse effects; D003485:Cyanates / Q000009:adverse effects; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000209:etiology*; D009783:Dermatitis, Occupational / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D017953:Isocyanates / Q000009:adverse effects*; D008297:Male; D009790:Occupations; D014051:Toluene 2,4-Diisocyanate / Q000009:adverse effects; D001559:Benzhydryl Compounds
chemical_list: D000485:Allergens; D000814:Aniline Compounds; D003485:Cyanates; D017953:Isocyanates; D014051:Toluene 2,4-Diisocyanate; C015262:1,6-hexamethylene diisocyanate; C015301:isophorone diisocyanate; C005969:4,4'-diphenylmethane diisocyanate; D001559:Benzhydryl Compounds; C009505:4,4'-diaminodiphenylmethane