Cashew nut dermatitis. An example of internal-external contact-type hypersensitivity
Ratner, J.H.; Spencer, S.K.; Grainge, J.M.
Archives of Dermatology 110(6): 921-923
1974
ISSN/ISBN: 0003-987X PMID: 4280272 Document Number: 81021
Five patients who had a positive reaction to Rhus oleoresin patch test antigen developed a generalised eczematous dermatitis after eating large amounts of raw cashew nuts. Of 4 tested 3 had positive patch test reactions to raw cashews and negative reactions to roasted cashews. A group of highly Rhus-positive healthy adults had positive patch test reactions to raw cashews whereas Rhus-negative and slightly Rhus-positive adults had no reaction to raw cashews. No dermatitis occurred in 2 Rhus-negative men who ate 450 g fresh raw cashew nuts during 6 h. 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 Rhus oleoresin and causes a generalised eruption when eaten in large quantities by persons highly sensitive to Rhus antigen.