[header] How to deal with toxic coworkers [title] Highlight their work. [step] Toxicity is often a sign of insecurity. By giving the co-worker credit or highlighting something that they've done, you may give them some semblance of positivity in their life, which could help with the toxicity. 
You may also find a friend you didn't think you could have. [substeps] For example, tell your boss all that your co-worker has done if you've worked together on a project.