Occupational allergy in greenhouse workers: sensitization to Tetranychus urticae.
BACKGROUND
Tetranychus urticae (TU) is a macroscopic mite which is found infesting a large number of plants of economic interest. It has rarely been described as a cause of occupational allergic disease in agricultural workers.


OBJECTIVE
To describe TU sensitization in greenhouse workers attending the outpatient allergy unit and its clinical associations, and to characterize the allergens involved.


METHODS
Twenty-four consecutive carnation greenhouse workers with allergy-related symptoms, referred to our outpatient clinic during a 6-month period, were included. We made the diagnostic extract from carnation leaves heavily infested with TU. Skin-prick test, specific IgE measurement and bronchial provocation test with TU extract were carried out in all subjects. Allergen characterization was achieved by SDS-PAGE (sodium dodecylsulfate-polyacrylamide gel electrophoresis) and immunoblotting.


RESULTS
Sixteen patients (66%) presented positive skin-prick test and specific IgE and were diagnosed allergic to TU. Fifteen patients suffered from bronchial asthma, 14 rhinitis and five urticaria. Twelve exhibited positive bronchial provocation test to the TU extract. On RAST-inhibition studies, there was no evidence of crossreactivity between TU extract and D. pteronyssinus. An allergen at 19 kDa was determined in the TU extract by SDS-PAGE immunoblotting studies.


CONCLUSIONS
TU could be an important occupational allergen in greenhouse workers showing allergic symptomatology. There is no crossreactivity between this mite and the house dust mite D. pteronyssinus.
Delgado
J
J
Unidad de Alergologia, Hospital El Tomillar, Sevilla, Spain.
Orta
J C
JC
Navarro
A M
AM
Conde
J
J
Martínez
A
A
Martínez
J
J
Palacios
R
R
D000293:Adolescent; D000818:Animals; D039741:Antigens, Dermatophagoides; D001249:Asthma / Q000276:immunology; D016535:Bronchial Hyperreactivity / Q000276:immunology; D003429:Cross Reactions; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007073:Immunoglobulin E / Q000032:analysis; D008925:Mites / Q000276:immunology*; D009784:Occupational Diseases / Q000276:immunology*; D012220:Rhinitis / Q000276:immunology; D012882:Skin Tests
D039741:Antigens, Dermatophagoides; D006023:Glycoproteins; D007073:Immunoglobulin E