teaser styling effects all content on /node page

if I create a post and apply italics to the post and the content is promoted, when you then browse to the home page where all the teasers are, virtually all of the content that flows below the new teaser adopts the italics formating. I narrowed down the problem to the last word in the teaser and the following word in the whole post. If I italicized the last word in the teaser, no problems. If I italicized the following word which does not appear in the teaser, no problem. But, if I italicized both those words, then the entirety of the home page that flows beyond that point adopts the applied formatting (italics, bold, underline, etc).
Any ideas?

Thanks