Rhus poisoning, the active principle of which is the complex radical urushiol, ranks highest among the causes of plant dermatoses and constitutes an occupational hazard for horticulturists, farmers and those engaged in clearing land, not to mention the infection of carefree ramblers in the woods. Though many efficacious methods exist for treating the eruption after it has occurred, little has been accomplished for prophylaxis. Potassium permanganate and ferric chloride discolor and pigment the skin; desensitizing injections of ascending doses of rhus toxin seem to be impracticable, if large numbers of field workers are involved.
An alkaline vanishing cream containing a nonirritant, nonstaining oxidizing agent such as sodium perborate or potassium periodate is now recommended1 as an effective preventive against poison ivy dermatitis. By incorporating either of these drugs in an ointment and applying it to the skin of the arms and the face before exposure, even those who are