Thresholds for Contact Allergy to a Rubber Accelerator: TETD-Determined by Serial Dilution Patch Testing and a...

Area of Science:

• Dermatology
• Toxicology
• Occupational Health

Background:

• Rubber accelerators, such as tetraethylthiuram disulfide (TETD), are common components in rubber gloves.
• These accelerators can cause allergic contact dermatitis (ACD) in susceptible individuals.
• Identifying the threshold for ACD induction is crucial for preventing occupational allergies.

Purpose of the Study:

• To determine the specific doses of TETD that induce allergic contact dermatitis.
• To compare the efficacy of patch testing versus a repeated occluded application test in simulating glove use for ACD assessment.
• To establish a dose-response relationship for TETD-induced ACD.

Main Methods:

• A multicenter study involving eight patients with known TETD allergy and eight controls.
• Patch testing with serial dilutions of TETD (1% down to 0.0041%).
• Repeated occluded application tests simulating glove use with TETD concentrations of 1%, 0.33%, and 0.11%.

Main Results:

• Three out of eight patients reacted to the lowest TETD dose (0.0041%, 1.6 μg/cm²) in patch tests.
• All patients exhibited reactions to all tested TETD concentrations in the repeated occluded application test.
• The estimated dose of TETD eliciting ACD in 10% of patients (ED10) was 0.75 μg/cm² via patch testing.

Conclusions:

• A TETD content of 0.75 μg/cm² in rubber gloves may be sufficient to induce allergic contact dermatitis.
• The repeated occluded application test is a valuable model for future studies on contact allergy to rubber accelerators.
• This study provides critical data for setting safe limits for TETD in consumer products to prevent allergic reactions.