title: Skincare products containing low concentrations of formaldehyde detected by the chromotropic acid method cannot be safely used in formaldehyde-allergic patients.
abstract: BACKGROUND
  Formaldehyde is a well-known contact sensitizer. Formaldehyde releasers are widely used preservatives in skincare products. It has been found that formaldehyde at concentrations allowed by the European Cosmetics Directive can cause allergic contact dermatitis. However, we still lack information on whether formaldehyde at low concentrations affects dermatitis in formaldehyde-allergic individuals.
  
  
  OBJECTIVE
  To study the effects of low concentrations of formaldehyde on irritant contact dermatitis in formaldehyde-allergic individuals.
  
  
  METHODS
  Fifteen formaldehyde-allergic individuals and a control group of 12 individuals without contact allergy to formaldehyde and formaldehyde releasers were included in the study. The individuals performed the repeated open application test (ROAT) during 4 weeks with four different moisturizers releasing formaldehyde in concentrations that had been determined as > 40, 20-40, 2·5-10 and 0 p.p.m. by the chromotropic acid (CA) spot test. Dimethyloldimethylhydantoin was used as a formaldehyde releaser in the moisturizers. The ROAT was performed on areas of experimentally induced sodium lauryl sulfate dermatitis. The study was double blind, controlled and randomized.
  
  
  RESULTS
  Nine of the 15 formaldehyde-allergic individuals had reappearance or worsening of dermatitis on the areas that were treated with moisturizers containing formaldehyde. No such reactions were observed in the control group (P < 0·001) or for the moisturizers without formaldehyde in the formaldehyde-allergic individuals (P < 0·001).
  
  
  CONCLUSIONS
  Our results demonstrate that the low concentrations of formaldehyde often found in skincare products by the CA method are sufficient to worsen an existing dermatitis in formaldehyde-allergic individuals.
authors.affiliation: Department of Occupational and Environmental Dermatology, Lund University, Skåne University Hospital, SE-20502, Malmö, Sweden.
authors.forename: I
authors.initials: I
authors.lastname: Hauksson
authors.affiliation: Department of Occupational and Environmental Dermatology, Lund University, Skåne University Hospital, SE-20502, Malmö, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Pontén
authors.affiliation: Department of Occupational and Environmental Dermatology, Lund University, Skåne University Hospital, SE-20502, Malmö, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Gruvberger
authors.affiliation: Department of Occupational and Environmental Dermatology, Lund University, Skåne University Hospital, SE-20502, Malmö, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Isaksson
authors.affiliation: Department of Occupational and Environmental Dermatology, Lund University, Skåne University Hospital, SE-20502, Malmö, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Engfeldt
authors.affiliation: Department of Occupational and Environmental Dermatology, Lund University, Skåne University Hospital, SE-20502, Malmö, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Bruze
mesh_terms: D000328:Adult; D000368:Aged; D003124:Colorimetry / Q000379:methods; D003358:Cosmetics / Q000009:adverse effects / Q000737:chemistry; D017453:Dermatitis, Irritant / Q000209:etiology*; D004311:Double-Blind Method; D004342:Drug Hypersensitivity / Q000209:etiology*; D005260:Female; D005557:Formaldehyde / Q000009:adverse effects* / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009282:Naphthalenesulfonates / Q000378:metabolism; D010328:Patch Tests; D011310:Preservatives, Pharmaceutical / Q000009:adverse effects* / Q000032:analysis; D017592:Skin Care / Q000009:adverse effects*
chemical_list: D003358:Cosmetics; D009282:Naphthalenesulfonates; D011310:Preservatives, Pharmaceutical; D005557:Formaldehyde; C020996:chromotropic acid