Anaphylaxis due to limpet ingestion.

BACKGROUND

The limpet, phylum Mollusca, is one of the most frequent sea mollusks in the Canary Islands. Limpet IgE hypersensitivity reactions have been described.

OBJECTIVE

To describe six patients with anaphylactic reactions due to limpet ingestion and to demonstrate by in vivo methods and by in vitro techniques specific IgE responses.

METHODS

Six subjects who developed severe bronchospasm 30 to 120 minutes after eating limpets were included in the present study. The antigenic material for the in vivo and in vitro studies was an extract of cooked limpet prepared in our laboratory. Skin prick tests were performed in all patients using commercially available aeroallergens, mollusk, and crustacean extracts; the same skin tests were performed using the extracts prepared in our laboratory. Specific IgE by CAP and RAST and CAP inhibition studies were also performed. Limpet contamination by mites was excluded through a commercial ELISA using monoclonal antibodies.

RESULTS

All patients had positive skin prick tests to D. pteronyssinus and cooked limpet extract and weak reactivity to cockroach and raw limpet extract. Specific IgE to mites and cooked limpet extract was also found using CAP and RAST techniques, respectively. The possible existence of common epitopes between limpet and D. pteronyssinus was excluded by CAP inhibition studies. Finally, no significant mite concentration was detected in the cooked limpet extract analyzed by a commercially available ELISA.

CONCLUSIONS

Limpet is a potentially dangerous allergen specially in patients sensitized to D. pteronyssinus.