Anaphylaxis to Cyphomandra betacea Sendth (tamarillo) in an obeche wood (Triplochiton scleroxylon)--allergic patient

Background Anaphylaxis after the first exposure to a food allergen is uncommon unless a cross-reaction is present. Objective To investigate a possible relationship between the fruit Cyphomandra betacea Sendth (commonly known as tamarillo) and the wood of Triplochiton scleroxylon (obeche) in a patient with allergic occupational bronchial asthma due to obeche wood who began to experience anaphylaxis episodes after eating tamarillo. Methods A 33-year-old carpenter exposed to obeche wood in his occupation was initially seen with rhinitis and bronchial asthma. The causal relationship of these symptoms to obeche wood exposure was investigated by means of peak flow monitoring and bronchial inhalation testing. Furthermore, the patient had 2 acute episodes of anaphylaxis a few minutes after eating salad containing tamarillo. He had never tasted tamarillo before. The allergologic study included skin prick tests, serum specific IgE determinations, bronchial challenges, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunoblotting. Results Results of skin prick tests with common aeroallergens were negative. Strong skin prick test responses were obtained with obeche and tamarillo. Results of bronchial challenge testing with obeche extract were positive. In tamarillo extract, a 28-kDa band appeared as the most relevant IgE-binding antigen. A similar band of 28 kDa happens to be frequently detected in obeche-allergic patients. Conclusion To our knowledge, this is the first reported case of anaphylaxis to tamarillo presented in a patient allergic to obeche, which raises the question of a new cross-reactivity antigen.