Active sensitization to dimethylthiocarbamylbenzothiazol sulphide: An unexpectedly strong rubber contact allergen

Abstract

AbstractBackgroundThe two dialkylthiocarbamyl benzothiazole sulphides, dimethyl‐thiocarbamylbenzothiazole sulphide (DMTBS) and diethylthio‐carbamylbenzothiazole sulphide (DETBS) were shown to be good markers of both thiuram and mercaptobenzothiazole sensitivity.ObjectivesTo investigate if DMTBS and/or DETBS could be better markers of contact allergy to common rubber additives than the ones currently used.MethodsSixty‐eight dermatitis patients were patch tested with DMTBS and DETBS, both at 1% in petrolatum (pet). Because of late reactions in 10 patients, these were retested to DMTBS and DETBS in serial dilutions. Tetramethylthiuram monosulphide (TMTM) 1.0% pet was also tested.ResultsAt the initial reading Days 3 and 7, no reactions were noted to DMTBS or DETBS. At retesting, 10 of the 68 (15%) patients reacted positively to lower concentrations of DMTBS than the initial test concentration. Seven of 8 also reacted to TMTM. Three of them had positive reactions to DEBTS. All 10 patients had reactions to more diluted solutions to DMBTS than to DEBTS (p = 0.0077; Mc‐Nemar test, two‐sided).ConclusionsResults speak for patch test sensitization to DMTBS with cross‐reactivity to TMTM and also DEBTS. DMTBS and DEBTS could be new markers of rubber allergy but a safe test concentration must be found.