Contact Allergy and Irritancy
Contact allergy to triclosan is uncommon.[37,38,39,40,41] In 1989, the Swiss Contact Dermatitis Research Group conducted a large 1-year study to examine the frequency of sensitization to commonly found preservatives in patients with suspected contact dermatitis. Triclosan was shown to have a low sensitizing potential as only 0.8% of the 2,295 patients tested had positive reactions. Several cases of patients who developed allergic contact dermatitis secondary to triclosan-containing products have been reported, including one case of a health care worker whose contact dermatitis from triclosan was confirmed by patch testing.[39,40,43,44,45] Wahlberg published a large series in 1976 that showed negative test results for 902 patients tested with 0.5% and 1.0% triclosan concentrations for 16 months but reported three cases of allergic contact dermatitis from triclosan at a 2.0% concentration among 1,100 patients tested for 17 months. Of these three individuals, two were shown to be sensitized to triclosan-containing deodorants. This is important because although triclosan is present in several deodorants sold in the United States, it is much more commonly present in soaps. The potential for an allergic contact dermatitis manifestation related to the use of a soap is lower than that related to the use of a deodorant, which is a leave-on product used in an occluded area.
The irritant potential of triclosan is also considered to be very low.[38,39,41,46,47] Detergents whose triclosan content is less than 2% are generally well tolerated. In one laboratory-based study of surgical hand disinfectants, a detergent containing 1% triclosan caused fewer subjective skin problems than did formulations containing an iodophor, 70% ethanol plus 0.5% chlorhexidine gluconate, or 4% chlorhexidine gluconate. Although there are published case reports of irritant dermatitis secondary to the use of triclosan-containing products, such products were also found to contain benzalkonium chloride, which is thought to have a greater irritant potential than triclosan has.[38,41,48,49]
Although it is thought that the allergenicity of triclosan is relatively low when compared to other biocides such as chlorhexidine or benzalkonium chloride, too few comparative trials have been performed to determine where triclosan falls in the allergenicity spectrum. Triclosan is generally patch-tested at a concentration of 2% in petrolatum. Overall, it is appears that the frequency of positive patch-test reactions to triclosan is low and that the prevalence of allergic and irritant contact dermatitis due to triclosan is very low, especially considering its widespread use in consumer and health care products.
Dermatitis. 2006;17(4):204-207. © 2006 American Contact Dermatitis Society
Cite this: Product Allergen Watch: Triclosan - Medscape - Dec 01, 2006.