ALTHOUGH there have been several reports in the recent literature concerning the use of para-aminobenzoic acid in the treatment of rickettsial diseases, the number of reported cases of Rocky Mountain spotted fever in which this drug was used is comparatively small. The first case was reported by Rose, Duane and Fischel.1 Then followed articles by Maroney and associates,2 Ross and Smith,3 Flinn and associates,4 and Hendricks and Peters.5 Experimentally, the drug has been proved to be rickettsia static,6 and it has been effective clinically in cases of epidemic typhus,7 endemic (murine) typhus8 and tsutsugamushi fever.9
The value of para-aminobenzoic acid in the treatment of Rocky Mountain spotted fever seems unquestioned. However, the drug has not yet been completely evaluated clinically, and many details regarding its use require clarification. The present study applies particularly to the methods of giving the drug, the