Pesticide patch test series for the assessment of allergic contact dermatitis among banana plantation workers in panama.

BACKGROUND: Irritant contact dermatitis and allergic contact dermatitis (ACD) are frequent among agricultural workers and require targeted interventions. Patch testing is necessary for differential diagnosis, but patch testing with pesticides is uncommon.
OBJECTIVE: This study explores the frequency of ACD and sensitization to pesticides among highly exposed banana plantation workers.
METHODS: Frequently and recently used pesticides on banana plantations in Divala, Panama, were documented. A pesticide patch test tray specific for this population was prepared. A structured interview was administered to 366 participants, followed by a complete skin examination. The pesticide patch test series, as well as a standard patch test series, was applied to 37 workers with dermatoses likely to be pesticide related and to 23 control workers without dermatoses.
RESULTS: The pesticide patch tests identified 15 cases (41%) of ACD (20 positive reactions) among the 37 workers diagnosed with pesticide dermatosis. Three controls had allergic reactions to pesticides (4 positive reactions). The pesticides were carbaryl (5 cases), benomyl (4 cases), ethoprophos (3), chlorothalonil (2), imazalil (2), glyphosate (2), thiabendazole (2), chlorpyrifos (1), oxyfluorfen (1), propiconazole (1), and tridemorph (1). Ethoprophos and tridemorph had not been previously identified as sensitizers. Thus, the prevalence of ACD was 0.03 (15 of 366). On the basis of observed prevalences of positive patch-test reactions among the subgroups with and without dermatoses, we estimated that > or = 16% of the entire population may be sensitized to pesticides.
CONCLUSION: Sensitization to pesticides among banana plantation workers is a frequent occupational health problem. Pesticide patch test trays should be used in assessing skin diseases in highly exposed workers.