Foot contact dermatitis: nitrofurazone as the main cause in a retrospective, cross-sectional study over a 16-year period from Turkey.

BACKGROUND: The major causative agents in allergic contact dermatitis of the foot may differ from country to country. Sufficient data on foot eczema in patients from Turkey are lacking.

OBJECTIVE: To identify the clinically relevant contact allergens in foot eczema and determine the role of patch test series and patients' own materials in the detection of the responsible allergens.

METHODS: Among 1753 patients patch tested between 1996 and 2012 in our clinic, 53 with suspected allergic foot eczema were enrolled in this retrospective, cross-sectional study. Forty nine patients were patch tested with the extended European baseline series, 49 with supplemental series including rubber, leather, topical drugs, textile, cosmetic series containing preservatives and emulgators and varnish/plastic/glue series, and 37 with their own substances.

RESULTS: Thirty of the 53 patch tested patients showing sensitization to at least one clinically relevant allergen were diagnosed with allergic foot eczema. The main eliciting agent was nitrofurazone (n = 8), followed by leather shoe allergens, ie, potassium dichromate (n = 6), p-tert-butylphenol formaldehyde resin and formaldehyde, in the second range. Rubber shoe allergens were less frequently observed (n = 3). In more than 1/3 of the patients, the causative agent could only be identified by testing the patient's own substances and/or supplemental series.

CONCLUSION: Nitrofurazone was the leading causative agent followed by leather shoe allergens. Pediatric patients were frequently sensitized with shoe allergens. Patch testing with patient's own substances had a critical value in the detection of the causative agent in a significant number of patients.