4,4'-Thiobis(2-tert-butyl-5-methylphenol), an antioxidant in medical devices that may cause allergic contact dermatitis.

Background: Antioxidants in medical devices, added to protect polymers or adhesives, may also cause contact dermatitis in some individuals.

Objectives: To present data on sensitization to 4,4'-thiobis(2-tert-butyl-5-methylphenol), an antioxidant detected in some types of medical devices, for six patients that experienced eczematous reactions to different medical devices.

Methods: Patch testing with 4,4'-thiobis(2-tert-butyl-5-methylphenol), 1% pet was performed. Gas chromatography-mass spectrometry (GC-MS) was used for identification of 4,4'-thiobis(2-tert-butyl-5-methylphenol) in different medical device products.

Results: Six patients with contact allergy to 4,4'-thiobis(2-tert-butyl-5-methylphenol) also had relevant contact allergic reactions to medical devices containing the antioxidant. The presence of the antioxidant in products was detected using GC-MS analysis.

Conclusions: The antioxidant 4,4'-thiobis(2-tert-butyl-5-methylphenol) may cause allergic contact dermatitis after exposure to different medical devices.