Patch testing with the <scp>J</scp>apanese baseline series 2015: A 4‐year experience

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>The Japanese baseline series (JBS), established in 1994, was updated in 2008 and 2015. The JBS 2015 is a modification of the thin‐layer rapid‐use epicutaneous (TRUE) test (SmartPractice Denmark, Hillerød, Denmark). No nationwide studies concerning the TRUE test have previously been reported.</jats:p></jats:sec><jats:sec><jats:title>Objectives</jats:title><jats:p>To determine the prevalence of sensitizations to JBS 2015 allergens from 2015 to 2018.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We investigated JBS 2015 patch test results using the web‐registered Skin Safety Care Information Network (SSCI‐Net) from April 2015 to March 2019.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Patch test results of 5865 patients were registered from 63 facilities. The five allergens with the highest positivity rates were gold sodium thiosulfate (GST; 25.7%), nickel sulfate (24.5%), urushiol (9.1%), <jats:italic>p‐</jats:italic>phenylenediamine (PPD; 8.9%), and cobalt chloride (8.4%). The five allergens with the lowest positivity rates were mercaptobenzothiazole (0.8%), formaldehyde (0.9%), paraben mix (1.1%), mercapto mix (1.1%), and PPD black rubber mix (1.4%).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Nickel sulfate and GST had the highest positivity rates. The JBS 2015, including a modified TRUE test, is suitable for baseline series patch testing.</jats:p></jats:sec>