Pustules in secondary syphilis

In an otherwise typical case of palmoplantar secondary syphilis, large intact pustules were also present. Spirochetes were demonstrated in these lesions by darkfield microscopy. The distinctive pathologic finding in the pustular lesions was migration of polymorphonuclear leukocytes into the epidermis, with formation of microabscesses. This pattern is the same as that seen in "framboesiform" secondary syphilis and in yaws.