In February 2007, an epidemic of severe dermatitis from Chinese recliner chairs and sofas started to unfold first in Finland and a few months later in the UK. Some patients reacted in patch tests (PTs) strongly to the material of their furniture, either leather or fabric. There have been hundreds of reports of chair or sofa dermatitis from Finland and the UK, with all cases linked to the same furniture factory in China. Clinical findings in both countries were very similar and unlike any known dermatosis. Many cases have been quite severe, resembling mycosis fungoides or septic infections, requiring hospitalization. Commercial PTs did not reveal the cause but a fungicide was strongly suspected, although such use was denied by the factory. The laboratory of Malmö University Dermatology Clinic has helped in the process by making thin layer chromatograms from sofa or chair materials and test substances of suspected chemicals. Finally, sachets marked with ‘mouldproof agent’ were found in varying numbers and distribution in the sofas. These contained dimethyl fumarate (DMF) which proved in skin tests to cause strong positive reactions with down to 0.01 dilution. Reports from other countries (Belgium, France, Ireland, Sweden and Spain) have since appeared, and the EU has banned the use of DMF in consumer products.