Triclosan exposure linked to allergies in children

Nov 15 2012

By Helen Albert, Senior medwireNews Reporter

Norwegian children with high levels of urinary triclosan are more likely to have allergies than children with lower levels, report researchers in Allergy.

In particular, the team found that 10-year-old children with high levels of exposure to the antibacterial chemical had an increased likelihood for having seasonal or inhalant allergies.

"Based on the 'hygiene hypothesis' of allergy in childhood, excessive use of triclosan may alter the commensal microbiota flora leading to impairment of normal maturation of the immune system," say Randi Bertelsen (Norwegian Institute of Public Health, Oslo) and colleagues.

Triclosan has also been shown to enhance allergic sensitization in previous animal studies and in a study of US children. Bertelsen and team recruited 623 10-year-old Norwegian children to assess whether urinary levels of triclosan, measured in one first morning void during 2001-2004, correlated with their levels of allergic sensitization.

Allergic sensitization was measured according to the presence of immunoglobulin (Ig)E antibodies to 15 common food or inhalant allergic triggers.

Children with the highest levels of urinary triclosan (fourth quartile) were twice as likely to show symptoms of allergic sensitization to seasonal or inhalant, but not food, allergens than children in the reference group (below detectable levels of triclosan). They were also almost twice as likely to have current rhinitis as those in the reference group. These differences were statistically significant.

In addition, each log₁₀ increase in triclosan level increased the risk for allergic sensitization and rhinitis by a significant 20%.

"These results are consistent with recent findings in other studies and provide additional evidence for an association between triclosan and allergy," write Bertelsen et al.

"In the future, longitudinal studies would be useful for evaluating the temporal association between triclosan and allergy development, and more experimental studies are needed to evaluate the mechanism of triclosan in relation to allergy development," they conclude.

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