title: Allergic potential of neutrals in unmodified colophony, and a method for their separation from resin acids.
abstract: An ion-exchange fractionation technique for the separation of total resin acid and neutral fractions of unmodified colophony is described. The allergic potential of these fractions was assessed by patch testing colophony-sensitive individuals, and this showed that both the neutral components and the resin acids play an important role in colophony sensitization. A greater frequency of positive reactions was obtained using the 60% colophony patch test preparation compared with the currently recommended 20% colophony preparation. Furthermore, some individuals were found to produce positive reactions to only the neutral components in colophony. We suggest that the use of a colophony patch test battery comprising resin acids, neutrals, oxidized resin acid and some colophony derivatives, will facilitate detection of colophony-sensitive individuals. Moreover, we consider that this will help to provide a better estimate of the prevalence of colophony dermatitis, which is currently underestimated.
authors.affiliation: Institute of Occupational Health, University of Birmingham, Edgbaston, U.K.
authors.forename: S
authors.initials: S
authors.lastname: Sadhra
authors.forename: I S
authors.initials: IS
authors.lastname: Foulds
mesh_terms: D005591:Chemical Fractionation; D017453:Dermatitis, Irritant / Q000276:immunology; D006801:Humans; D012116:Resins, Plant / Q000009:adverse effects* / Q000737:chemistry; D012867:Skin / Q000276:immunology; D012882:Skin Tests / Q000379:methods*; D013638:Tars / Q000009:adverse effects*
chemical_list: D012116:Resins, Plant; D013638:Tars; C013893:rosin