Hypersensitivity to thimerosal: the sensitizing moiety.

There has been increasing interest in characterizing the sensitizing moiety of thimerosal [TIM], following the finding that patients with photosensitivity to piroxicam are allergic to the thiosalicylic acid [TIO] moiety of TIM. For this purpose, the authors have conducted 2 studies in TIM-sensitive patients. In the 1st, of 175 patients tested with TIO and ammoniated mercuric chloride [HGAM], 45.