1/3. tobacco allergy: demonstration of cross-reactivity with other members of solanaceae family and mugwort pollen.BACKGROUND: tobacco is a plant belonging to the solanaceae family. This plant is usually used as a contact insecticide for several infestations in some areas, such as the Canary islands. Allergy induced by inhalation of this plant is unusual. Identification of the potential allergen in growing areas is essential. OBJECTIVE: We report a patient with occupational sensitivity to an aqueous solution of cut tobacco whose clinical manifestations were rhinoconjunctivitis and urticaria. Past medical history was significant for seasonal allergic rhinoconjunctivitis to mugwort pollen and oral allergy syndrome with avocado. methods: Green tobacco and cured tobacco leaf extracts were prepared, skin prick tests were performed with green tobacco, cured tobacco leaf extracts, and certain aeroallergens. Conjunctival challenge test was carried out with green tobacco and cured tobacco leaf extract. serum-specific IgE against tobacco leaf was performed by commercial CAP. CAP inhibition experiments were carried out with tobacco and artemisia vulgaris. RESULTS: skin prick tests and conjunctival challenge tests with green tobacco and cured tobacco leaf extracts were positive, as well as serum-specific IgE by CAP, indicating an IgE-mediated sensitization. CAP inhibition experiments were carried out and it was found that tobacco, mugwort pollen, and tomato extracts inhibited the binding of the patient's serum to solid-phase tobacco leaf. No inhibition was observed when alternaria, D. pteronyssinus, and potato were used as control inhibitors. Inhibition of immunoCAP to mugwort was obtained with mugwort and tobacco extracts and no cross-reactivity to D. pteronyssinus was shown. CONCLUSION: The results suggest that tobacco can induce IgE-mediated reactions that are mediated by the existence of common antigenic epitopes between tobacco and mugwort pollen. This allergy can be a hazard of employment in the agricultural areas.- - - - - - - - - - ranking = 1keywords = potato (Clic here for more details about this article) |
2/3. Allergic contact urticaria from raw potato.A 19-year-old man exhibited symptoms of immediate urticaria and angioedema related to contact with raw potato. A prick-by-prick test with potato pulp and rub test were positive. Specific IgE to potato was positive (class 2).- - - - - - - - - - ranking = 7keywords = potato (Clic here for more details about this article) |
3/3. Biochemical and clinical studies in a case of contact urticaria to potato.Contact urticaria to potato was confirmed by skin testing in a 26-year-old male with atopic dermatitis, birch-pollen rhinoconjunctivitis and a history of immediate finger itching upon handling raw potato. The potato peel was non-reactive. The urticarial reactivity to potato could be transferred by the patient's serum in a Prausnitz-Kustner test, indicating an immunological etiology. Electrophoretic and chromatographic examination of extracts from homogenized potatoes (unexposed to synthetic fertilizers and insecticides) revealed allergenic activity in a heat-labile macromolecular fraction with a mass of 20-30 kdalton migrating towards the anode during agarose gel electrophoresis at pH 8.6 with a mobility similar to that of human alpha 1-antitrypsin. The technique used for preliminary fractionation of the allergenic activity in a potato extract, similar to crossed immunoelectrophoresis, appears to be a simple and widely applicable technique for the characterization of proteins with this biological activity. A partially purified fraction with allergenic activity, seemingly more stable than the activity in crude homogenates, was obtained by gel filtration and preparative agarose gel electrophoresis. When an antihistamine was also injected, the urticarial reaction to the protein fraction was less pronounced. Pretreatment of the skin with compound 48/80, a histamine releaser, blocked the reaction. histamine thus seems to be the major vasoactive substance mediating the contact urticarial response to potato antigen in this patient.- - - - - - - - - - ranking = 11keywords = potato (Clic here for more details about this article) |