Inhibitory effect of zinc oxide on contact allergy due to colophony

• Published in: Contact dermatitis Vol. 23; no. 5; p. 346
• Main Authors: Söderberg, T A, Elmros, T, Gref, R, Hallmans, G
• Format: Journal Article
• Language: English
• Published: England 01.11.1990
• Subjects: Adult; Dermatitis, Contact - etiology; Dermatitis, Contact - prevention & control; Female; Humans; Male; Middle Aged; Occlusive Dressings; Patch Tests; Resins, Plant - adverse effects; Zinc Oxide - administration & dosage; Zinc Oxide - adverse effects
• ISSN: 0105-1873
• DOI: 10.1111/j.1600-0536.1990.tb05170.x

Contact allergy to a wound dressing with an adhesive mass consisting of colophony, zinc oxide and rubber (Mezinc) was studied in 179 patients with a history of eczema. 12 patients were found to be allergic to colophony, whereas only 4 of these patients also showed a positive patch test reaction to the wound dressing. 14 patients with verified moderate contact allergy to colophony were patch tested with adhesive mass (10%), Portuguese colophony (10%), zinc oxide (10%), purified resin acids (10%), and Portuguese colophony (10%), in combination with zinc oxide. Only 3 patients reacted to the adhesive mass, whereas all patients showed a positive patch test reaction to Portuguese colophony. A combination of zinc oxide (10%) with Portuguese colophony (10%) provoked a positive patch test reaction in only 5 of these 14 patients. An allergic reaction to abietic acid (90-95% purity) was found in 7 patients and to neoabietic acid (99 + %) in 3 patients, whereas no reactions to dehydroabietic (99 + %), isopimaric (99 + %) or levopimaric acids (98 + %) were found.