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: Corticosteroids different from paramethasone also produced hypersensitivity reactions in these patients ; however , a few of them were tolerated .
### Output Text:
Corticosteroids different from <span class="chemical">paramethasone</span> also produced hypersensitivity reactions in these patients ; however , a few of them were tolerated . 