Allergy to pine processionary caterpillar (Thaumetopoea pityocampa) in children

Contact with pine processionary caterpillar (Thaumetopoea pityocampa) induces dermatitis usually located in exposed areas through a toxic-irritative mechanism. Over the last few years an immediate hypersensitivity mechanism have mainly been demonstrated in adult patients. However, there are few studies carried out in children.

To evaluate a group of 16 children who experienced allergic reactions after exposure to pine processionary caterpillar.

All patients underwent allergy testing through skin prick test. Serum specific IgE determination was performed by EAST technique. The molecular mass of the IgE -binding bands was studied by SDS-PAGE Immunoblotting.

Skin prick test with the caterpillar extract was positive in all patients. Specific IgE was positive (higher than 0.35 kU/L) in 15 patients' sera. Western blotting showed several IgE-binding bands with molecular mass values ranging from 17.5 to 168 kDa. Electrophoretic mobility of some of the relevant allergens was related to the conditions of sample preparation (reduced or non-reduced).

The results of this study demonstrate the existence of an allergic IgE-mediated mechanism caused by pine processionary caterpillar proteins. Airborne urticating hairs of this animal should be considered as seasonal inhalant allergen, which is able to induce allergic pathologies in children who frequent pine areas.