[Retrospective diagnosis of anthrax by intradermal reaction].

The authors report a detailed study of utilization of a skin test with anthraxin to perform a retrospective diagnosis of anthrax in humans who suffered from anthrax 45 days to 31 years after recovery. For a total of 884 persons studied, 762 showed a positive skin test (86.2%). This index was 92.8% for persons tested 45 days to 3 years after convalescence, 82.8% 4 to 15 years after convalescence and 72.7% 16-31 years after recovery. The site of the primary carbuncle on the skin of the fingers, hands, face and neck gave an index of positivity (88.2%) statistically greater (p = 99%) than by localization of the carbuncle on arms, forearms, trunk and legs (77.3%).