Turpentine-induced hypersensitivity to peppermint oil.

After a dental operation a former laboratory technician was referred to our clinic because of swelling of his tongue, lips, and gingival mucosa. Patch testing with the ICDRG standard test battery gave positive reactions to colophony, balsam of Peru, and turpentine peroxides. Further patch testing revealed hypersensitivity to peppermint oil (an ingredient of several dental preparations) due to the sensitizing properties of three ingredients: alpha-pinene, limonene, and phellandrene. These compounds also occur in turpentine oil, a substance used in the patient's laboratory.