PREVALENCE OF POSITIVE SKIN-TESTS TO SNAI LS IN PATIENTS PRESENTING WITH ALLERGIC RESPIRATORY MANIFESTATIONS - CORRELATIONS WITH HOUSE-DUSTMITE ALLERGY AND CLINICAL IMPLICATIONS

A high frequency of sensitization to house dust mites was reported in patients with a history of anaphylactic reactions after eating snails. The hypothesis of a cross-reactivity between these two allergens was suggested. The objective of this study was to determine the exact inci dence of positive skin tests to snail allergens in a group of patients presenting with apparently allergic respiratory symptoms, to verify t he existence of a Link with hypersensitivity to house dust mites and t o evaluate the clinical significance of a positive skin test. A prick test with a snail extract was systematically performed in 312 patients recluiring cutaneous allergological assessment for respiratory; manif estations. Patients who presented a positive reaction to the snail ext ract (induration > 4 mm) were questioned about the possible developmen t of anaphylactic manifestations alter ingestion of gastropods. 239 pa tients (77%) had at least one positive test to a respiratory allergen and 163 (52%) were sensitized to house dust mites. The skin test to sn ail allergen was positive in 14 patients (4,5%). All but one of these patients were sensitized to house dust mites. 6 of these 14 patients h ad already eaten snarls at least once and 4 of them had presented anap hylactic manifestations several minutes after ingestion. This study th erefore confirms the existence of a significant link between sensitiza tion to house dust mites and to snail allergens. Although the frequenc y of this association is relatively low, it should be systematically i nvestigated, by clinical interview and skin tests, due to the potentia l severity of the manifestations following ingestion of snails.