Formaldehyde exposure and patterns of concomitant contact allergy to formaldehyde and formaldehyde-releasers.

BACKGROUND

Formaldehyde and formaldehyde-releasers are widely used in consumer products and may often cause contact allergy.

OBJECTIVE

To investigate the prevalence of concomitant contact allergy to formaldehyde and formaldehyde-releasers in dermatitis patients, and to determine the sources of formaldehyde exposure based on personal and occupational products obtained from dermatitis patients.

METHODS

Patch test data from referred dermatitis patients with a positive patch test reaction to formaldehyde or formaldehyde-releasers were analysed. For the period 2000-2008, the formaldehyde content in products obtained from formaldehyde-allergic patients was analysed by chromotropic acid test and/or acetylacetone test.

RESULTS

Patients allergic to a formaldehyde-releaser often had simultaneous contact allergy to formaldehyde. Other combinations were also prevalent. In patients who reacted to more than two formaldehyde-releasers, nearly all reacted simultaneously to formaldehyde. Seventy-five percent of the formaldehyde-allergic patients used a product that contained formaldehyde. The main source of formaldehyde exposure was cosmetics (78%).

CONCLUSIONS

Concomitant contact allergy to formaldehyde and formaldehyde-releaser remains common. Furthermore, contact allergy to a formaldehyde-releaser was nearly always concomitant with another formaldehyde-releaser. Formaldehyde was commonly found in personal products used by formaldehyde-allergic patients.