[Allergens used in skin tests in Mexico].

BACKGROUND: Immunotherapy is the only recognized causal treatment for allergies. It is prepared on an individual basis, based on the patient's clinical history and the result of the skin prick test (SPT). An adequate composition of the allergens with which to test the patient is crucial for an optimal diagnosis.

OBJECTIVE: To know allergens used in tests in allergy practices in Mexico.

MATERIALS AND METHOD: A national survey among all members of the Colegio Mexicano de Inmunología Clínica y Alergia (CMICA) and of the Colegio Mexicano de Pediatras Especialistas en Inmunología Clínica y Alergia (COMPEDIA) was carried out. In a second phase respondents were asked to send in the composition of a routine SPT in their clinic. The results are presented descriptively and the frequency is calculated by which certain allergen is tested in the interviewed practices.

RESULTS: A survey response rate of 61 (17%) was obtained and 54% showed their SPT content. Weeds' representation in the SPT seems adequate; Atriplex is tested in all allergy practices. Some trees that show cross-reactivity might be eliminated from the SPT, but 20% doesn't test for Cynodon nor Holcus, and 25% doesn't for important allergens as cat, dog and cockroach. House dust and tobacco are still tested with certain frequency.

CONCLUSIONS: The selection of which allergens to test in a SPT is based on multiple data, that change continuously with new investigations and discoveries. Our specialty is the most indicated--and obligated--to adjust constantly to these changes to have the best diagnostic tool to detect specific allergies.