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: We also carried out oral and parenteral challenges with other corticosteroids and found intolerance to some of them .
### Output Text:
We also carried out oral and parenteral challenges with other <span class="chemical">corticosteroids</span> and found intolerance to some of them . 