I recently had a psoriasis flare up, I went to the doctor

Hello -

That isn't normal.

However it is known that a steroid injection can cause fat to atrophy, and that may be why the fat in the breast has "shrunk" as a result of the injection.

Ideally this will get better with time.

This is called "lipoatrophy" after steroid injection.

I sincerely hope that I have helped you, and that I have earned my 5 star rating today! Please remember to rate my service by selecting the 5 stars at the top of the screen ( rating me now does not close your question). We can continue here until you are satisfied, simply use the reply box and let me know. Thank you!

Both are unusual.

Ideally temporary, as most people notice return after a few months.

No other concerns. Ideally you would see return of this area slowly over 3-6 months.