Delayed hypersensitivity cross-reactions between Sporothrix schenckii and Ceratocystis species in sporotrichotic patients

Abstract
Cutaneous delayed hypersensitivity to antigens prepared from S. schenckii and several Ceratocystis spp., including C. stenoceras, C. ulmi, C. ips and C. minor, was tested in 14 patients with known cutaneous sporotrichosis. Extensive cross-reactions were observed. Nonsporotrichotic people (controls) did not react to these antigens. The correlation coefficient between antigens of S. schenckii and each Ceratocystis spp. was calculated from the areas of the cutaneous reactions. Among the Ceratocystis spp. tested, the correlation coefficient between S. schenckii and C. stenoceras was 0.91. [These results have relevance to the diagnostic specificity of the sporotrichin skin test.].