Non-occupational allergy caused by the pine processionary caterpillar (Thaumetopoea pityocampa).
Contact with the pine processionary caterpillar induces dermatitis, usually located in exposed areas, and, less frequently, ocular lesions through a toxic-irritative mechanism. Recently, the existence of an immediate hypersensitivity mechanism has been demonstrated, mainly in occupationally exposed patients.


OBJECTIVE
To present four patients who experienced allergic reactions (urticaria-angioedema and rhinitis-asthma) after non-occupational exposure to pine processionary caterpillar.


METHODS
The four patients underwent allergy testing through skin prick tests (SPT), specific IgE detection and SDS-PAGE immunoblotting. One patient also underwent a specific bronchial challenge test with the pine processionary antigen.


RESULTS
In all patients, both SPT with the caterpillar extract and specific IgE were positive. Western blotting showed several IgE-binding bands with molecular mass values ranging from 18 to 107 kDa. A shift in the electrophoretic mobility of some of the relevant allergens occurred under the presence of a reductive agent (beta -mercaptoethanol). The specific bronchial challenge test with pine processionary antigen performed in one of the patients also produced positive results.


CONCLUSIONS
The results of this study show an immunologic IgE-mediated immediate hypersensitivity mechanism in these reactions. The processionary caterpillar's airborne urticating hairs or spicules should be considered, at least in some locations, not only as contact and occupational allergens, but also as seasonal aeroallergens.
Fuentes Aparicio
V
V
Allergy, General Hospital Universitary Gregorio Marañón. Madrid. Spain. victoriafuente@terra.es
de Barrio Fernández
M
M
Rubio Sotés
M
M
Rodríguez Paredes
A
A
Martínez Molero
M I
MI
Zapatero Remón
L
L
Bartolomé Zavala
B
B
D000328:Adult; D000485:Allergens / Q000009:adverse effects; D000799:Angioedema / Q000209:etiology*; D000825:Animal Structures; D000818:Animals; D001249:Asthma / Q000209:etiology*; D001985:Bronchial Provocation Tests; D002648:Child; D017449:Dermatitis, Allergic Contact / Q000209:etiology*; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000209:etiology*; D007073:Immunoglobulin E / Q000097:blood; D019476:Insect Proteins / Q000009:adverse effects* / Q000276:immunology / Q000302:isolation & purification; D007814:Larva / Q000737:chemistry / Q000276:immunology / Q000648:ultrastructure; D008297:Male; D008875:Middle Aged; D009036:Moths / Q000254:growth & development*; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology*; D012882:Skin Tests; D013030:Spain; D014020:Tissue Extracts / Q000009:adverse effects; D014581:Urticaria / Q000209:etiology*
D000485:Allergens; D019476:Insect Proteins; D014020:Tissue Extracts; D007073:Immunoglobulin E; C047449:thaumetopoein protein, insect