ASTHMA AFTER CONSUMPTION OF SNAILS IN HOUSE-DUST-MITE-ALLERGIC PATIENTS - A CASE OF IGE CROSS-REACTIVITY

A group of 28 patients from Italy was studied who had asthma after con sumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitizatio n to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-re active with house-dust mite. In contrast, the mite RAST was not signif icantly inhibited by snail. This indicates that house-dust mite was th e sensitizing agent. Immunoblot analyses revealed multiple bands in sn ail extract recognized by IgE. In contrast to what has been described for crossreactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen In these patients. The observ ations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, the refore, be advisable to screen mite-allergic asthma patients for aller gy to snail and other invertebrate animal foods.