Allergy to castor bean (Ricinus communis) - Presentation of 2 cases of not work-related hypersensitivity and review

Two case reports about respiratory allergy caused by castor bran (Ricinus communis) products are presented. A 31-year-old banker developed glottis edema after cultivating his pass plats with a common, castor bean-containing fertilizer. A 28-years-old teacher experienced intermittent attacks of rhinoconjunctivitis and Quincke edema of the neck. The causative agent was identified to be a necklace purchased in Mexico. It was made from seeds of the castor oil plant but remained unrecognized until she had an acute reaction in the allergist office. In both cases skin prick tests were strongly positive and specific IgE could be detected. The oil of castor bean did not elicite reactions in the skin tests. The castor bran is one of the most potent allergens causing type I allergy in man. Usually patients encounter the allergen at their work or by living in the vicinity of castor bean processing farms. Several, even epidemic asthma outbreaks were described in oil-processing mills, dock workers, coffee-processing workers as well as in farmers, merchants, fertilizer retailers, draymen, felt and upholstery workers, drivers and gardeners. Our cases indicate that allergens of Ricinus can elicite allergic symptoms even in persons, who do no have occupational contact with castor bean. The patients's exposure to castor bean can happen in exotic (mexican necklace) or in common (grass fertilizer) settings.