In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Concomitant use of oral prednisone and topical beclomethasone may increase the risk of developing hoarseness or candidiasis .
### Output Text:
Concomitant use of oral <span class="chemical">prednisone</span> and topical <span class="chemical">beclomethasone</span> may increase the risk of developing hoarseness or candidiasis . 