Related Experiment Video
Updated: Aug 1, 2026

A Push-pull Protocol to Reduce Colonization of Bird Nest Boxes by Honey Bees
Published on: September 4, 2016
Results of Concurrent Patch Testing of Brazilian and Chinese Propolis
Emma M van Oers1, Norbertus A Ipenburg2, Anton de Groot2
1Amsterdam University Medical Centers, Amsterdam, The Netherlands.
Background:
In Amsterdam, a steep increase in positive reactions to propolis in the European baseline series was observed from 2.8% in 2020 to 16.4% in 2023. We hypothesised that this was caused by the replacement of Chinese propolis by Brazilian propolis.
Objectives:
To test this hypothesis and to compare rates of positive patch tests to Brazilian propolis with those to Chinese popolis.
Patients And Methods:
In a prospective study, 2 commercial Chinese propolis patch test samples were tested in consecutive patients in addition to Brazilian propolis.
Results:
Of 239 patients patch tested, 57 (23.8%) had a positive reaction to Brazilian propolis, and 9 (3.8%) to Chinese propolis. Of the 57 reactions to Brazilian propolis, only 2 (3.5%) were found to be clinically relevant, versus 3/9 (33.3%) for Chinese propolis. Patients reacting to Brazilian propolis had significantly more co-reactivities to fragrance mixes 1 and 2 and to limonene hydroperoxides than propolis B-negative individuals.
Conclusions:
The results confirm our hypothesis that the observed increase in positive patch tests to propolis between 2020 and 2023 was the result of the switch from Chinese to Brazilian propolis. The rates of reactions to both propolis samples from China were significantly lower than to Brazilian propolis.
Related Concept Videos
Test Cross
Complementation Tests
Organisms heterozygous for different mutations are crossed pairwise in all combinations. If present on different genes, the mutations can complement each other by providing the missing...
Goodness-of-Fit Test
Test for Homogeneity
Multiple Comparison Tests
It would be easy to compare two samples using a significance alpha level of 0.05. In other words, there is only one sample pair to be compared. However, it would be difficult to identify a significantly different sample if the number...
Bonferroni Test
The means of different samples are first paired in all possible combinations.
The null hypothesis of the...

