Display the result of a content posted to a table in the mysql database where it already has its css..but it does not work on the frontend

As I said above my script works perfect but when I call in frontend

$_POST['descricao'];

She did not read the css that comes with this variable.

At the bank you are registered like this:

<p>Essa parte n&atilde;o &eacute; it&aacute;lico</p>
<p>&nbsp;</p>
<p><em>Mas essa aqui &eacute;</em></p>

And he is not leaving italics.