Thespesia populnea dermatitis.

BACKGROUND

The allergenic properties of milo wood have not been known before now.

OBJECTIVE

We investigated the wood and elucidated the structure of its main sensitizer.

METHODS

A bowl turner suffered from allergic contact dermatitis over years. Wood shavings were extracted, and the constituents were isolated, purified, and identified. The sensitizing capacity of the main compound was determined experimentally in guinea pigs.

RESULTS

Initially, patch tests with sawdust suspensions and the isolated main constituent were positive. During the course of the study, however, the patient developed tolerance. The main component of milo wood was identified as a new mansonone: 7-hydroxy-2,3,5,6-tetrahydro-3,6, 9-trimethylnaphtho [1,8 bc] pyran-4,8-dione. In the sensitizing experiments, it showed to be a moderate sensitizer.

CONCLUSION

Extensive and long-lasting exposure to certain sensitizers may cause the phenomenon of hardening as has been shown in the wood working industry.