chancre

The primary lesion of syphilis, (or lesions resembling this). Clinical manifestations: 1) begins at the site of cutaneous or mucosal infection after an incubation period of 10-30 days 2) the initial lesion is papular, dull red, hard & painless 3) the papule generally ulcerates, with healing over 4-6 weeks Laboratory: 1) darkfield microscopy of scraping for Treponema pallidum 2) Treponema microdentium (endogenous flora) may confound microscopic examination of oral ulcers

References

Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999.