Contact allergy in Indonesian patients with foot eczema

Background: Shoe dermatitis is a form of contact dermatitis resulting from exposure to shoes (1). Diagnostic is based on patient history, the presence of skin lesions, positive patch test reactions to allergens in the 'screening' tray, and the absence of dermatitis in a patient wearing proper substitute shoes (2). Allergens and types of shoes responsible may vary, depending on manufacturing techniques (3, 4), climatic conditions and indigenous traditions (5, 6). This study focuses primarily on as yet unexplored shoe dermatitis cases in Indonesia. Objectives: To determine the prevalence of shoe dermatitis diagnosed in the Dermatology Outpatient Clinic, Sardjito University Hospital, Yogyakarta, Indonesia over a period of 3 years and to identify the responsible allergens. Methods: All patients meeting screening criteria for possible shoe dermatitis were patch tested with European baseline series, shoe series, and additional series based on earlier studies of Indonesian leather and shoe manufacturers (7, 8); some were also patch tested with their own shoe materials and shoe extracts. Results: Sixty-four (7.1%) of 903 patients with foot skin disorders were diagnosed with shoe dermatitis based on the screening criteria. Forty-eight patients were patch tested with three series of allergens: 16 with their own shoe materials and 2 with their own shoe extracts. Of 48 patch tested shoe dermatitis patients, 25 (52.1%) showed positive patch test reactions to one or more allergens. In 21 (43.75%) this was corroborated by positive patch test reactions to their own shoe materials/shoe extract or a clear relation between exposure to the allergen or improvement of the skin lesion after elimination. The most frequent relevant sensitizers were rubber allergens followed by preservatives, shoe adhesives and leather materials. Conclusions: Shoe dermatitis iscommonin Indonesia.Using three series of patch tests we identified responsible allergens and patterns of sensitization in Indonesian shoe dermatitis patients