Reflections on clinical relevance of cross-reactivity between house dust mite, molluscs and crustacean

Introduction: Cross-reactivity between house dust mite and molluscs or crustacean has been reported in the past, mainly French and Italian publications are related to this subject. In our region this house-dust mite associated food allergy seems to play a less important role. Patients: 33 patients consulting our outpatients department because of a clinically relevant type-I-sensitization to house dust mite were included in the study. The relevance of a possible house dust mite related food allergy due to cross-reactive IgE antibodies was studied by a questionnaire, skin prick tests and in vitro assays, as well. Results: 29 patients consumed shrimps, but only 2 patients reported on adverse reactions after consumption. Snails were rarely eaten, only one person regularly eats snails, 10 persons sporadically, but 22 persons never eat snails. No adverse effects were reported after consumption of snails. The two persons with clinical symptoms after consumption of shrimps had positive skin prick test results in the prick to prick test, but specific IgE was detected in one case. Conclusion: In our opinion patients suffering from a sensitization to house dust mite should be informed about possible related food allergies to molluscs and crustacean in spite of the fact that such adverse reactions are quite rare. Therefore this related food allergy can not be compared to the mugwort/celery syndrome. Patients with a food allergy after consumption of invertebrates should be examined if they are sensitized to house dust mite because in adults food allergy is mainly due to cross-reactivity between inhalative and food allergens.