Formaldehyde 2% is not a useful means of detecting allergy to formaldehyde releasers— results of the ESSCA network, 2015-2018

Heather Whitehouse, Wolfgang Uter, Johannes Geier, Barbara Ballmer-Weber, Andrea Bauer, Susan Cooper, Magdalena Czarnecka-Operacz, Simon Dagmar, Heinrich Dickel, Anna Belloni Fortina, Rosella Gallo, Ana M. Giménez-Arnau, Graham A. Johnston, Francesca Laresse Filon, Vera Mahler, Maria Pesonen, Thomas Rustemeyer, Marie L.A. Schuttelaar, Skaidra Valiukevičienė, Elke WeisshaarThomas Werfel, Mark Wilkinson

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Background: Studies suggest that patch testing with formaldehyde releasers (FRs) gives significant additional information to formaldehyde 1% aq. and should be considered for addition to the European baseline series (EBS). It is not known if this is also true for formaldehyde 2% aq. Objectives: To determine the frequency of sensitization to formaldehyde 2% aq. and co-reactivity with FRs. To establish whether there is justification for including FRs in the EBS. Materials and Methods: A 4-year, multi-center retrospective analysis of patients with positive patch test reactions to formaldehyde 2% aq. and five FRs. Results: A maximum of 15 067 patients were tested to formaldehyde 2% aq. and at least one FR. The percentage of isolated reactions to FR, without co-reactivity to, formaldehyde 2% aq. for each FR were: 46.8% for quarternium-15 1% pet.; 67.4% imidazolidinyl urea 2% pet.; 64% diazolidinyl urea 2% pet.; 83.3% 1,3-dimethylol-5, 5-dimethyl hydantoin (DMDM) hydantoin 2% pet. and 96.3% 2-bromo-2-nitropropane-1,3-diol 0.5% pet. This demonstrates that co-reactivity varies between FRs and formaldehyde, from being virtually non-existent in 2-bromo-2-nitropropane-1,3-diol 0.5% pet. (Cohen's kappa: 0, 95% confidence interval [CI] −0.02 to 0.02)], to only weak concordance for quaternium-15 [Cohen's kappa: 0.22, 95%CI 0.16 to 0.28)], where Cohen's kappa value of 1 would indicate full concordance. Conclusions: Formaldehyde 2% aq. is an inadequate screen for contact allergy to the formaldehyde releasers, which should be considered for inclusion in any series dependant on the frequency of reactions to and relevance of each individual allergen.

Original languageEnglish
Pages (from-to)95-102
Number of pages8
JournalContact dermatitis
Issue number2
Publication statusPublished - Feb 2021


  • 2-bromo-2-nitropropane-1,3-diol
  • DMDM hydantoin
  • contact allergy
  • cosmetics
  • diazolidinyl urea
  • formaldehyde formaldehyde releasers
  • imidazolidinyl urea
  • quaternium-15

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