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

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

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.

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.

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%).

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.