Trends in patch-test results and allergen changes in the standard series: A Mayo Clinic 5-year retrospective review (January 1, 2006, to December 31, 2010)

Contact allergy in cheilitis

“…For each patient, the treating dermatologist determined the specific antigens or series to be tested. Included series were the standard series, the oral flavorings and preservatives series, the oral complete series, and other series, including personal products used by the patient (Appendix S1, online).…”

“…The treating physician determined the relevance of each positive result on the basis of the patient's history and known exposures. Weak, strong, and extreme reactions at the final reading were considered to represent positive reactions; macular erythema was considered positive if the result was shown to be relevant …”

Benzalkonium Chloride

“…29 From 2006 through 2010, BAK had a positive patch test rate of 8.8% and an irritancy rate of 0.7% (3115 patients tested). 28 We compared data from 2006 through 2010 with data from 2001 through 2005 and did not find a significant difference in the rate of allergenicity to BAK. 28 However, there was a significant increase (P G 0.05) in the rate of allergic patch test results from 1998 through 2000 (5.5%) and 2001 through 2005 (8.3%).…”

“…28 We compared data from 2006 through 2010 with data from 2001 through 2005 and did not find a significant difference in the rate of allergenicity to BAK. 28 However, there was a significant increase (P G 0.05) in the rate of allergic patch test results from 1998 through 2000 (5.5%) and 2001 through 2005 (8.3%). 29 The difference between the rate of allergenicity from 1998 through 2000 (5.5%) and 2006 through 2010 (8.8%) was also statistically significant (P = 0.005).…”

“…23 Even with this evidence, the potential for BAK to cause allergic contact dermatitis (ACD) remains under debate, 24Y27 as positive patch test results have been postulated to be misinterpretations of irritant responses. 24 Few reports highlight the significance of BAK as an allergen; however, in our experience of patch testing with the standard series, BAK was one of the top 10 most frequent allergens: number 9 in 2006 through 2010 28 and up from number 10 in 2001 through 2005. 29 For this reason, we retrospectively reviewed our database to determine the prevalence and relevance of this emerging allergen.…”