Positive patch test reactions to formaldehyde releasers indicating contact allergy to formaldehyde

Patterns of positive patch test reactions to formaldehyde and formaldehyde releasers at the Finnish Institute of Occupational Health from 2007 to 2020

BACKGROUND

Formaldehyde is an important contact sensitizer. Formaldehyde releasing substances induce positive reactions in formaldehyde-allergic patients, but there are also reactions independent of formaldehyde allergy. In an earlier study, stronger formaldehyde reactions led to more positive reactions to quaternium-15.

OBJECTIVES

To analyze patterns of positive patch test reactions to formaldehyde and different formaldehyde releasers.

METHODS

Patch test files of 1497 patients investigated during the period November 2007-August 2020 were retrospectively reviewed for positive reactions to formaldehyde and its releasers. During the study period, almost all (≥99.3%) patients were tested with a formaldehyde dilution series and six formaldehyde releasers.

RESULTS

Ninety-three patients tested positive to formaldehyde; 80% of these had positive reactions to at least one formaldehyde releaser, most often benzylhemiformal. There were only nine independent contact allergies to formaldehyde releasers. There were only two reactions to 2-bromo-2-nitropropane-1,3-diol and they occurred in formaldehyde-negative patients. In patients with extreme (+++) reactions to formaldehyde, concomitant positive reactions to any of the other 11 investigated formaldehyde releasers were more common than in patients with milder formaldehyde reactions.

CONCLUSIONS

Strong formaldehyde reactions were associated with positive reactions to formaldehyde releasers.

Formaldehyde-releasers: relationship to formaldehyde contact allergy. Metalworking fluids and remainder. Part 1

This is part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy. Formaldehyde-releasers used in metalworking fluids (MWF) and a group of releasers not presented in previous articles are discussed. Here, in Part 1 of the article, there is a short overview of the composition and functions of MWF, the function of biocides in them, and adverse reactions to MWF. In addition, the releasers in MWF that have caused contact allergy are presented with CAS, synonyms, molecular formula, chemical structure, applications, patch test studies, and amount of formaldehyde released by them. In Part 2 of the article, the relationship between formaldehyde-releasers used in MWF and formaldehyde contact allergy is discussed as are data on miscellaneous releasers not previously presented, followed by a discussion of Parts 1 and 2 of the article.

Hand dermatitis: a focus on allergic contact dermatitis to biocides

Hand dermatitis is a common disease of the skin resulting in significantly decreased quality of life. Allergic contact dermatitis is a frequent cause of hand dermatitis. Recent studies have revealed that biocides used as preservatives are frequent allergens affecting the hands. This article reviews common biocides implicated in hand dermatitis.