Toxic thrombocytopenic purpura following local sulphathiazole therapy.

In spite of the universal use of sulphonamides there have apparently been reports of the occurrence of purpura following their administration on only twenty-two occasions. In fourteen cases the thrombocytes were found to be reduced in number, absent from blood films or below 100,000 per c.mm.; in four cases the thrombocyte count exceeded 125,000 per c.mm. and in four the count was not recorded. In all cases the drug was given by mouth and the amount producing purpura varied between 4 and 45 gm. In six cases purpura followed interrupted administration, the interval varying between one day and three years. The literature on the subject has recently been referred to more fully by Sherlock and White (1944). The case here reported is of interest in that thrombocytopenic purpura followed the local application of a 5 per cent. sulphathiazole ointment, and for the light which the investigations throw upon the mechanism of the condition.