Background: Potato allergy has been described rarely, generally in relation to the Oral Allergy Syndrome (OAS). Adults with seasonal allergic rhinitis have been reported in whom peeling of raw potatoes causes oculonasal symptoms, wheezing, and contact urticaria. Skin testing with fresh fruits and vegetables has been recommended in cases of OAS, although the sensitivity of commercial potato extract is reportedly equal to that of fresh potato.
Case report: This report describes a 4-year-old with raw potato-induced anaphylaxis. He rapidly developed urticaria, angioedema, respiratory distress, vomiting and diarrhea after biting into a raw potato that was being used for painting in preschool. Review of systems is significant for viral-induced wheezing, but no symptoms suggestive of seasonal allergic rhinitis were evident. His mother has a history of seasonal allergic rhinitis and contact urticaria with raw potato. Skin testing to commercial potato extract was negative and skin testing to fresh potato by the prick + prick method was markedly positive. Skin testing to birch tree was negative. An open challenge to a small amount of cooked potato was negative. Food challenge to raw potato was not considered indicated in this case of immediate anaphylaxis to a single food.
Conclusions: This patient had clinical and skin test reactivity to raw and uncooked potato in the absence of OAS. The patient will be followed for the development of seasonal allergic rhinitis.