Quantification of patch test reactions by transcutaneous PO2 measurement.

The usefulness of transcutaneous oxygen tension (tc-PO2) measurement for quantification of positive patch test reactions was studied. A significant correlation was found between the visual grading and the quantitative tc-PO2 values. Tc-PO2 discriminated between visual grade 0 to 1+, 1+ to 2+, and 2+ to 3+ reactions. The results obtained by this method were compared with those obtained by other quantitative methods. Tc-PO2 measurement can be regarded as complementary to the laser Doppler technique, since it lacks the sensitivity of the laser Doppler technique in the range in negative to 1+ patch reactions, but it does discriminate between 2+ and stronger reactions.