Value of patch testing with indigenous battery of allergens in shoe dermatitis

Abstract

Objective To explore the potential allergens used in our domestic shoe industry and to determine the efficiency of indigenously prepared battery of allergens in shoe dermatitis. Patients and methods A comprehensive list of 49 chemicals used in local processing and manufacturing of footwear was acquired from local sources. Potential irritants were excluded and a finished battery of 20 allergens relevant to our industrial environment was prepared by using standard techniques. Fifty patients and same number of control subjects were   enrolled in the study for patch testing using Finn chambers and polyethylene IQ chambers. Results were read using standard protocol at 1 hour, 48 hours, 4th day, and 7th day. A pre tested, structured questionnaire was filled for each patient. Data were analyzed using SPSS version 12.0 for statistical analysis. Chi square test was applied for comparative analysis between patients and controls. Results Out of 50 patients 33 (66%) were found to be allergic to 14 different chemicals present in indigenous test battery as opposed to 4 (8%) in control group (p<.0001, chi square test).  Fifteen (30%) patients were reactive to additives used in processing and manufacturing of rubber. Eight (16%) patients were sensitive to agents used in tanning the leather. Four (8%) patients exhibited sensitivity to both leather and rubber and 6 (12%) patients were allergic to the chemicals present in resins, glues, plastics, dyes and metals.  No reaction was observed at the site of application of blank chamber and vehicle. Conclusion The indigenous battery is reliable, cost effective and flexible to adapt to changes in exposure and to introduction of new allergens in market. It would be prudent to recommend exploring the other industries like perfume, garments, and rubber, etc. on similar lines.