Harmful effect of immunotherapy in children with combined snail and mite allergy.

BACKGROUND

With respect to allergy, the possibility of cross-reactivity between snail and mite is well recognized, and anecdotal reports suggesting that allergen immunotherapy with mite extract can worsen snail-induced allergy exist.

OBJECTIVE

We describe the effect of immunotherapy in 4 children with snail-mite allergy.

METHODS

Four children (1 boy and 3 girls; 9-13 years of age) had consistent clinical histories (mild immediate respiratory symptoms after ingestion) and positive skin reactions for allergy to snail. They also had mite-induced asthma and were therefore prescribed subcutaneous specific immunotherapy and subsequently followed.

RESULTS

Several months (8-25) after starting immunotherapy, all children experienced life-threatening reactions, anaphylaxis, and respiratory failure after inadvertent ingestion of snail. Skin reactivity to the fresh food increased in all patients.

CONCLUSIONS

This observation confirms that in patients with combined mite-snail allergy, immunotherapy should be avoided.