Some recent reports identify fumaic acid esters as an enviorenmental contaminant causing contact urticaria and allergic dermatitis. From literature I gather scattered information that such molecules are also found in many edibles, and medicinal plants. Therefore, I just wonder if any one knows a data base, or a review, on the matural occurance of fumarates in plants. This information could be of help in avoiding skin allergigies in sentive patients by just avoiding contacts with them, or by not eating them. Any help will be greatly appreciated.