Antifungal shoe chemical linked to foot dermatitis
MedWire News: Contact dermatitis of the foot has been linked to increasing use of an antifungal chemical in footwear, researchers caution in the International Journal of Dermatology.
The team reports a case study of a 37-year-old woman with severe eczema and blistering on the dorsum and soles of her feet following the purchase of a new pair of shoes. The patient also had lesions on the back of her foot where the sandal strap was in contact with her skin, and the back of her fingers, and reported fever and headache.
The eczema did not respond to general or topical corticosteroid therapy, topical antimicrobial treatment, or wet dressings, and were present for more than 3 months, write Massimo Gola (University of Florence, Italy) and co-authors.
Patch testing revealed a positive reaction after 96 hours to the methyl ester of fumaric acid, dimethyl fumarate (DMF), a fungicide used to protect goods during transport and preserve leather. The patient strongly reacted to DMF at a concentration of 0.1% and showed a weaker response to DMF 0.01%. She also had a positive reaction to patch tests with pieces of her shoes.
The woman was therefore diagnosed with acute contact dermatitis in reaction to DMF, the researchers say.
Of concern, analysis of the patient's shoes revealed a DMF concentration of approximately 740 mg/kg, which is significantly higher than the 0.1 mg/kg concentration in goods that is currently allowed by European legislation.
Noting that high concentrations of DMF have been increasingly detected in furniture, clothing, and shoes imported from China, Gola et al write: "For this reason, it is important to pay attention to the consequences of using the products described above and also bags and other leather objects from China."
They conclude: "We have reported this case in order to avoid an increase in the number of contact dermatitis cases and to stimulate an augmentation on global preventive measures against DMF exposure, and it is of note that this allergen is not included actually in most series for patch testing."
By Lynda Williams