Epidemio-allergological study in 155 cases of footwear dermatitis

Background : Footwear dermatitis represents a distinct and common group among all types of contact dermatitis cases seen in India. This ailment, however, often remains undiagnosed, misdiagnosed or empirically diagnosed without pinpointing the contributory allergens.
Aims : This study was undertaken to detect the epidemio-allergological pattern of footwear dermatitis in India.
Methods : A total number of 155 cases with footwear dermatitis were evaluated from July 2005 to June 2006, by detailed history and clinical examination. They were patch tested using Indian Standard Battery (ISB) approved by the Contact and Occupational Dermatoses Forum of India (CODFI) with pre- and post patch-test counseling.
Results : The proportion of footwear dermatitis was 24.22% (n=155) among a total of 640 patients patch tested during that period. Females [61.93% (n=96)] were commonly affected than males [38.06% (n=59)]. The ages ranged from 8 to 75 years. The age group that predominantly involved was the fifth decade [24.52% (n=38)]. Occupationwise housewives were most commonly involved [47.48 (n=66)]. Contributory allergens in order of frequency were: potassium dichromate, 45.8% (n=71); cobalt chloride, 38.06% (n=59); paraphenylenediamine, 32.25% (n=50); epoxy resin, 20% (n=31); black rubber mix, 20% (n=31); nickel sulfate, 14.83% (n=23); mercaptobenzothiazole, 12.9% (n=20); colophony, 11.6% (n=18); thiuram mix, 10.32 % (n=16); p-tert-butyl-formaldehyde resin, 9.67% (n=15); and formaldehyde, 4.5% (n=7). Among the different categories of footwear allergens, the highest positivity was shown by leather and leather-related chemicals in 61.9% cases (n=96).
Conclusion : Footwear dermatitis, a common dermatosis, is mostly caused by leather processing chemicals, metal buckles, black dyes of shoes and socks, adhesives, plastic, rubber shoes and polishing agents in order of frequency.