Patch test results of the <scp>E</scp>uropean baseline series among patients with occupational contact dermatitis across <scp>E</scp>urope – analyses of the <scp>E</scp>uropean <scp>S</scp>urveillance <scp>S</scp>ystem on <scp>C</scp>ontact <scp>A</scp>llergy network, 2002–2010