No, you really can't. On the other hand, if the author intended that section to stand out, you don't want to ignore that information and withhold it from future readers.
What you can do is format it differently from the rest of the text. For example, if you're averaging a 68-character line throughout normal paragraphs, you could reasonably use shorter lines, like 58 characters, for the italicized section. Going a step further, you could shorten the lines and indent them a space or two as well. This will give a clear signal to future readers and converters that this section is to be treated specially.