Abstract

SANTOS, Natacha  and  PLACIDO, José Luís. Sensitization to Tetranychus urticae in the North of Portugal. Rev Port Imunoalergologia [online]. 2014, vol.22, n.3, pp.207-213. ISSN 0871-9721.

Introduction: Tetranychus urticae is a phytophagus mite found in the leaves of numerous plants and an important plague in agriculture. A high sensitization rate, as well as symptoms of respiratory and cutaneous allergy, has been shown both in occupational exposure and in the general population, with low cross‑reactivity with house dust mites. However, no data exists concerning the Portuguese population. Aims: to evaluate the frequency of sensitization to Tetranychus urticae in patients followed in an Immunoallergy Department in the north of Portugal, and the pattern of co‑sensitization with other mites. Methods: We performed skin prick tests with Tetranychus urticae 2mg/mL extract (Leti©) and a standardized panel of airborne allergens consisting of mites, animal dander, tree, grass and weed pollen, and fungus. A skin prick test with a wheal size equal or higher than 3mm was considered positive. Data analyses were performed using SPSS® version 18.0 for Mac. Association between sensitization frequencies was evaluated with Qui‑square test. Results: The study was undertaken between January 21st and March 11th 2010, with a total of 196 patients tested, mean age (SD) 30.8 (17.0) years old, 61.2% female, 82.3% with a positive test to at least one extract. We report that 38.3% were sensitized to Tetranychus urticae, being this the fifth most prevalent allergen sensitization after house dust and storage mites. Of patients sensitized to Tetranychus urticae, 80% were sensitized to other mites, with a significant association, but lesser than between other mites phylogenetically closer; 4% were monossensitized. Conclusions: There is a high prevalence of sensitization to Tetranychus urticae, which cannot be fully explained by crossreactivity. Future studies of skin prick test validation with this extract and assessing clinical relevance to this mite are needed

Keywords : Mites; sensitization; skin prick tests; Tetranychus urticae.

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