Contact dermatitis from Grevillea 'Robyn Gordon'.

Grevillea 'Robyn Gordon' is an Australian hybrid plant which may cause allergic contact dermatitis. Over the past 8 years, it has been planted extensively in Australia and is now being exported to the United States and other Western countries. Recently, an explosion in incidence of contact dermatitis due to this plant has been seen. 24 patients who were suspected of being sensitive to it were patch tested to fresh plant and extracts with confirmation of sensitivity. A cross sensitivity to Toxicodendron was demonstrated clinically and on patch testing. The allergen in Toxicodendron, 3 pentadecylcatechol, is closely linked in chemical structure to 5-pentadecylresorcinol, present in Grevillea banksii and tridecylresorcinol in Grevillea robusta. Patch testing in patients sensitive to Grevillea 'Robyn Gordon' with tridecylresorcinol produced positive reactions, thus implicating the sensitizing rôle of long chain alkyl resorcinols in Grevillea 'Robyn Gordon' allergy. There is a likelihood that this sensitizing potential extends to other plants of the Grevillea genus, e.g., Grevillea robusta. With the spread of Grevillea 'Robyn Gordon' to other markets, this problem will become increasingly common.