Prescribed Desonide Topical for Eyebrow Seborrheic Dermatitis

(female)
I have severe eyebrow SD and I use desonide. I’ve been told by my dermatologist to apply it twice daily until it gets under control.

1. How close in time can I apply steroid creams without causing skin thinning?
2. What would you say is the upper limit of the length of time that I can use it?
3. Let’s say I use the desonide for about a week, and then stop for a couple of weeks, and then return to it for a week, am I starting over in terms of the length of time that I can use a steroid cream when I return to it? How much time should pass before I can safely start reusing a steroid cream?
4. What is the mechanism of action of steroid creams and how exactly do they cause skin thinning? (Feel free to get technical and use medical jargon.)

Thank you.

Your doctor should’ve given you application instructions, but I generally tell my patients that 3 or 4 treatments 12 hours apart is my usual limit for topical steroids. Seborrhea is produced by overactive skin proliferation which, like psoriasis, responds to steroids on the schedule I just reported. I do not know more than that for your case.