Immunodiffusion studies of morphologically similar dermatophyte species.

PLEOMORPHISM AND INCONSISTENT, OR LACK OF, SPORULATION POSE MAJOR DIFFI CULTIES TO MYCOLOGISTS ATTEMPTING TO IDENTIFY DERMATOPHYTES. UNTIL RECEN TLY, IDENTIFICATION WAS BASED ALMOST EXCLUSIVELY ON MORPHOLOGIC CRITERIA IN RECENT YEARS, BIOCHEMICAL TESTS HAVE PROVEN USEFUL FOR DISTINGUISHING CERTAIN DERMATOPHYTES, BUT THE ABSENCE OF DISTINGUISHING MORPHOLOGICAL OR BIOCHEMICAL QUALITIES AMONG CERTAIN GROUPS OF DERMATOPHYTES, HAS MADE MYCOLOGISTS INCREASINGLY AWARE OF THE NEED TO EVALUATE OTHER CRITERIA TO IDENTIFY DERMATOPHYTES RAPIDLY AND RELIABLY. THE RECENT SUCCESS IN USING EXOANTIGENS TO IDENTIFY SPECIFICALLY AND RAPIDLY TYPICAL AND ATYPICAL SPORULATING OR NONSPORULATING MYCELIAL FORM CULTURES OF BLASTOMYCES DER MATITIDES, COCCIDIOIDES IMMITIS, AND HISTOPLASMA CAPSULATUM, PROMPTED US TO DETERMINE WHETHER SPECIES-SPECIFIC EXOANTIGENS OCCUR AMONG DERMATOPHY TES AND, IF SO, WHETHER THEY COULD BE ROUTINELY AND PRACTICALLY USED FOR DIAGNOSTIC PURPOSES