Cashew Nut Dermatitis

Abstract

Five patients who were exquisitely sensitive to<i>Rhus</i>antigen 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 "<i>Rhus</i>-positive" healthy adult volunteers had positive patch test reactions to raw cashews, while "<i>Rhus</i>-negative" and slightly<i>Rhus</i>-positive volunteers had no reaction to raw cashews. No dermatitis could be produced by feeding large amounts of raw cashew nuts to two<i>Rhus</i>-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 to<i>Rhus</i>oleoresin and causes a generalized eruption when ingested in large quantities by people highly sensitive to<i>Rhus</i>antigen.