Is Unmodified Gum Rosin the Best Screening Material For Rosin Allergy?

Unmodified gum rosin is traditionally used in the standard tray when screening for contact allergy to rosin (colophony). It is a useful screening material, but additional testing with other rosins, such as gum rosin of different sources and tall oil rosin, detects more cases. Additional testing with Venice turpentine is also useful. Rosin has a complex chemical composition and oxidation products of resin acids in gum rosin have been identified as contact allergens. Synthesis of the main allergen found is in progress. New allergens might be created by modification of rosin. Thus, the main component in maleic-modified rosin was shown to be a potent sensitizer in animal experiments. Exposure to rosin products at work is important for the prognosis of dermatitis in patients. Chemical analysis of suspected products may therefore be a helpful tool.