How do you determine the duration and taper of systemic corticosteroids when you add them alongside antibiotics for orbital cellulitis?

There is no 'standard of care' answer for this. My personal preference is the following:

• Pediatric patients -- 0.25 to 0.5 mg/kg dexamethasone daily (given in AM) for up to 3 days, starting the day after source control/cultures from surgery. Higher dose/longer duration if very inflamed, and lower dose/consider only 1-2 days if less inflamed or generally healing quickly. If you prefer to give throughout the day, you could do 0.1-0.3 mg/kg q 6-8 hours for up to 3 days.
• Adult patients -- 40-80 mg IV Solumedrol daily for up to 3 days, followed by oral prednisone taper over a week. Same as for kids, generally the lower end of this dosing unless very inflamed, and starting AFTER surgical source control/cultures.

I am not sure why this obsession with giving 'steroids' in the context of a bacterial infection? When you look at the logic, I am not convinced there is any. If I have a bacterial infection on my finger or wherever, I do not prescribe, and I would not take prednisone or dexamethasone, so why use steroids here? Seems like a bad idea.