Utilidad de las pruebas cutáneas por punción (prick test) con extracto de guante, extracto crudo de látex y proteínas purificadas (pseudoheveína, heveína, forma molecular de la heveína y heveína modificada químicamente) en el diagnóstico de alergia al látex. Estudio de fase II

Introduction: Frequent surgical operations on children have shown an increase in allergy to latex in risk groups, specially if these surgeries are practiced at early ages. Objective: To state the usefulness of skin tests, through prick test, with glove extract, latex raw extract and purified proteins (such as pseudoheveine, molecular type of heveine, and chemically-modified heveine). Material and methods: From December 2004 to February 2005, 60 children were studied, having been previously classified according to their clinical records as: high-risk patients and clinical symptomatology of exposition to latex products (group I); low-risk patients without symptomatology of exposition to latex products (group II); or test (control) group. very patient having previously signed a consent letter, was applied a questionnaire identifying family and personal atopy, clinical symptomatology expressed by the exposition to latex products. The patients were practiced skin tests and through the skin prick test, with glove extract, latex raw extract, and purified proteins. Results: The results of this show that skin tests through the prick method with glove extraction in concentrations between 200 and 300 μg/mL, and in purified proteins with chemically-modified heveine in a concentration of 50 μg/mL, are the most proper compounds to determine allergy to latex. No systemic reaction was observed in the patients during the practice of skin tests. Discussion: Skin tests with glove extract in a concentration of 200 μg/mL gave sensitivity of 70% and specificity of 95%. With glove extract in a concentration of 300 μg/mL, it was obtained 705 of sensitivity and 98% of specificity. With regard to purified latex proteins the highest value was obtained by chemically modified heveine, in a concentration of 50 μg/mL, and with a sensitivity of 70% and specificity of 98%. Conclusions: The results in this study are proven with regard to sensitivity and specificity of latex extracts and purified proteins in order to be used in diagnosing allergy to latex. The security of the study was confirmed because there were no systemic reactions when carrying out skin tests. It is important to count upon a good, very carefully, performed clinical record. However, this is not just enough to establish a definite diagnosis about allergy to latex. It is always necessary to correlate the clinical records to the results from the skin test performed on latex extracts and purified proteins.