Trichloroethylene Hypersensitivity Syndrome Is Potentially Mediated through Its Metabolite Chloral Hydrate.

Background: We documented previously the entity of trichloroethylene (TCE) hypersensitivity syndrome (THS) in occupational workers.

Objectives: To identify the culprit causative compound, determine the type of hypersensitivity of THS, and establish a screening test for subjects at risk of THS.

Methods: TCE and its main metabolites chloral hydrate (CH), trichloroethanol (TCOH) and trichloroacetic acid (TCA) were used as allergens at different concentrations in skin patch tests.