The authors have declared no conflicts.
Patch testing with 2.0% (0.60 mg/cm2) formaldehyde instead of 1.0% (0.30 mg/cm2) detects significantly more contact allergy
Article first published online: 4 OCT 2012
© 2012 John Wiley & Sons A/S
Volume 68, Issue 1, pages 50–53, January 2013
How to Cite
Pontén, A., Aalto-Korte, K., Agner, T., Andersen, K. E., Giménez-Arnau, A. M., Gonçalo, M., Goossens, A., Johansen, J. D., Le Coz, C. J., Maibach, H. I., Rustemeyer, T., White, I. R. and Bruze, M. (2013), Patch testing with 2.0% (0.60 mg/cm2) formaldehyde instead of 1.0% (0.30 mg/cm2) detects significantly more contact allergy. Contact Dermatitis, 68: 50–53. doi: 10.1111/j.1600-0536.2012.02169.x
- Issue published online: 11 DEC 2012
- Article first published online: 4 OCT 2012
- Accepted for publication 11 August 2012
- contact allergy;
- patch test
Background.The currently used patch test concentration for formaldehyde is 1.0% (wt/vol) in water. However, clinical experience and previous studies suggest that 1.0% might be insufficient for detecting an optimized number of clinically relevant cases of contact allergy to formaldehyde.
Objectives.To validate earlier patch test results for comparison of 1% (wt/vol) and 2% (wt/vol) formaldehyde in water, and to investigate co-reactivity with quaternium-15.
Materials and methods.In 12 dermatology clinics, 3591 patients were routinely patch tested simultaneously with 2.0% (wt/vol) (0.60 mg/cm2) and 1.0% (wt/vol) (0.30 mg/cm2) formaldehyde. Micropipettes were used for delivering the exact dosage of the allergen.
Results.Significantly more patients reacted to 2.0% formaldehyde than to 1.0% (3.4% versus 1.8%, p < 0.001). Overall, there were no sex differences between those reacting positively to 2.0% and 1.0%. Of 25 quaternium-15-positive patients, 4 (0.1%) reacted positively without reacting to formaldehyde.
Conclusion.On the basis of the results of this multicentre study, as well as of previous studies, it can be suggested that 2.0% (wt/vol) in water formaldehyde should be used in routine patch testing in the baseline series.