[Rosewood allergy due to an arm bracelet and a recorder].

A 40-year-old woman developed dermatitis of the left forearm after wearing a bracelet manufactured from Brazilian rosewood (Dalbergia nigra All.). Swelling of the lips, itching and vesicles recurred when she played a recorder made from the same timber some years later. Epicutaneous tests were strongly positive after 120 h with 2 of the wood constituents: R-4-methoxydalbergione and S-4,4'-dimethoxydalbergione. The third quinone (S-4'-hydroxy-4-methoxydalbergione) only elicited a weak reaction. Shavings of the wooden bracelet extracted with benzene and ethanol and separation of the residues by thin layer chromatography yielded all 3 dalbergiones in remarkable amounts (congruent to 0,8%). Cross-reactions to the chemically near related R-3,4-dimethoxydalbergione, known as the strongest sensitiser of the dalbergione group, were not obtained, although guinea pig experiments had revealed cross-reactivities. Of the racemic 4-methoxydalbergione the dextrorotatory form elicited stronger responses than the S-form.