患者男,31岁,因齿龈溃疡11天来诊。患者出现溃疡时自觉症状不明显,曾在单位诊所服用维生素Ｂ2、牛黄解毒片1周未见好转。曾有婚外性交、接吻及舔阴史,否认同性恋,性伴中有梅毒患者,因此患者严格使用避孕套,泌尿道和外生殖器均未出现自觉症状和体征。体检:一般状况尚可,发育正常 Patient male, 31 years old, diagnosed with gum ulcer for 11 days. In patients with ulcers when the symptoms are not obvious, once in the unit clinic taking vitamin B2, bezoar detoxification tablets did not improve for 1 week. Have had extramarital intercourse, kissing and cunnilingus history, denied homosexuality, syphilis among partners, so patients with strict condom use, urinary tract and external genitalia did not appear subjective symptoms and signs. Physical examination: the general condition is acceptable, normal development