Cashew Nut Dermatitis

Five patients who were exquisitely sensitive toRhusantigen developed a generalized eczematous dermatitis after eating large amounts of "raw" cashew nuts. Three of four tested had positive patch test reactions to raw cashews and negative reactions to roasted cashews. A group of highly "Rhus-positive" healthy adult volunteers had positive patch test reactions to raw cashews, while "Rhus-negative" and slightlyRhus-positive volunteers had no reaction to raw cashews. No dermatitis could be produced by feeding large amounts of raw cashew nuts to twoRhus-negative volunteers. The raw cashew nuts sold in organic food stores contain appreciable amounts of cashew nut shell oil on their surfaces. The oil is antigenically similar toRhusoleoresin and causes a generalized eruption when ingested in large quantities by people highly sensitive toRhusantigen.