Pesticide contact dermatitis in agricultural workers of Himachal Pradesh (India).

Background: Common pesticides used in the region by agricultural workers may cause contact allergy.

Methods: Thirty agricultural workers with a history of pesticide exposure and dermatitis involving the face, neck, trunk or extremities, and 20 controls comprising 2 groups of 10 subjects each, group 1 with dermatitis and no exposure to pesticides, and group 2 with neither exposure to pesticides nor dermatitis, were patch tested with 10 pesticides commonly used in the region by use of the Finn Chamber method.

Results: The 30 patients, 20 of whom were male, aged 30-77 years, had dermatitis for 1 month to 18 years, with relapses and remissions. Seasonal exacerbation was present in 18 patients. Six patients attributed aggravation of their dermatitis to pesticide exposure, and 2 of these reacted positively to propiconazole. Positive patch test reactions to pesticides occurred in 10 patients, but not in controls. Thiuram was the commonest sensitizer (4 patients). Three patients were sensitized to propiconazole, and 2 patients reacted positively to metaldehyde. Formaldehyde, mercaptobenzothiazole, cypermethrin and isoproturon gave positive reactions in 1 patient each.

Conclusion: The sensitizing potential of pesticides remains a concern. Apparently, pesticide contact dermatitis is more common than expected, but remains under-reported, as the implicated pesticides vary across regions and according to the crop patterns.