Predicting visual assessment of allergic patch test reactions by non-invasive measurements

The quantification of allergic patch test reactions to several compounds wa s evaluated on patients using laser Doppler velocimetry (LDV), transepiderm al water loss and colorimetry. The correlation between visual sco res and i nstrumental measurements was investigated by:the implementation of a modern statistical method: a classification tree. The LDV showed the highest corr elation with the severity of the reaction. The best prediction model was ob tained when the data of the three instruments were considered together. Usi ng the classification tree methodology, a model of classification, independ ent of human observation, was developed. The technique can not only predict an allergic reaction for a new patient, but can also give a measure of how reliable its predictions are. This new method, when entirely standardised and approved, could help in the harmonisation of patch test reactions in di fferent laboratories, thus allowing a more homogenous interpretation of the se reactions. Copyright (C) 2000 S. Karger AG, Basel.