Dimethyl fumarate contact dermatitis of the foot: an increasingly widespread disease

Background Dimethyl fumarate (DMF) has been recognized as an extremely potent irritant and sensitizer found in sachets inside furniture. The first skin manifestations were correlated to contact with sofas, chairs, and other furniture. In these last years, some papers have reported a development of allergic contact dermatitis on the foot caused by DMF present in high concentration in shoes made in China. Methods We report the case of a 37-year-old woman who presented with severe eczema on the foot shortly after having bought a new pair of shoes. The diagnosis was performed by patch tests with DMF in several dilutions, with pieces of internal and external parts of the shoes, and by chemical analysis of the shoes. Results In the last three years, goods containing DMF increased diffusely despite the augmentation on global preventive measures by Europe. Conclusions Therefore, new cases of contact dermatitis could be dependent on DMF, and it is of note that this allergen is not included in most series for patch testing.