Contact allergy to 5,5 '-di-tert-butyl-2,2 '-dihydroxy-(hydroxymethyl)-dibenzyl ethers, sensitizers in p-tert-butylphenol-formaldehyde resin

Allergy to p-tert-butylphenol-formaldehyde resin (PTBP-F-R) is not rare. Th is resin consists of a large number of substances, most of which are still unknown. More knowledge about the sensitizers in the resin is a good basis for development of diagnosis, treatment and prevention. The aim of this inv estigation was to study allergens in PTBP-F-R by isolation of some medium m olecular weight substances from the resin and patch testing these in indivi duals hypersensitive to PTBP-F-R. 2 isolated substances were shown to be al lergens in PTBP-F-R, 5,5'-di-tert-butyl-2,2'-dihydroxy-3,3 '-dihydroxymethy l-dibenzyl ether and 5,5'-di-tert-butyl-2,2'-dihydroxy-3-hydroxymethyl-dibe nzyl ether. 13 patients hypersensitive to PTBP-F-R were patch tested with s erial dilutions of 5,5'-di-tert-butyl-2,2'-dihydroxy-3,3'-dihydroxymethyl-d ibenzyl ether and 12 of them reacted positively. 12 patients hypersensitive to PTBP-F-R were patch tested with serial dilutions of 5,5'-di-tert-butyl- 2,2'-dihydroxy-3-hydroxymethyl-dibenzyl ether and 11 of them reacted positi vely. Positive patch test reactions were seen down to 0.0000025 mmolexl(-1) (approximate to 0.01 ppm) for both 5,5'-di-tert-butyl-2,2'-dihydroxy-3,3 ' -dihydroxymethyl-dibenzyl ether and 5,5'-di-tert-butyl-2,2'-dihydroxy-3-lly droxymethyl-dibenzyl ether in the most sensitive patient. HPLC analysis of 2 PTBP-F-Rs showed the presence of 1.0-1.7% w/w 5,5'-di-tert-butyl-2,2'-dih ydroxy-3,3'-dihydroxymethyl-dibenzyl ether and 0.75-0.90% w/w 5,5'-di-tert- butyl-2,2'-dihydroxy-3-hydroxymethyl-dibenzyl ether in the resins.