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: This occlusion occurred after EACA therapy in a patient with SAH and histopathological documentation of recurrent SAH .
### Output Text:
This occlusion occurred after <span class="chemical">EACA</span> therapy in a patient with SAH and histopathological documentation of recurrent SAH . 