What am I allergic too? Botox user face injected Friday r..4 days later Prednisone injection for back. Urticaria rash on face

Prednisone Injected ir the back area.. Steroids make me very jumpy and emotional. The office where I went for the steroid injection saw the upper leg rash which appeared less than 4 minutes after I was done.. I was told to call if anything was worse.That night I had trouble with bladder like there was a UTI.Due to be stretched so my urine can pass.This was 4 days at a new place.. After being a user of Botox inside and out how do I know if I if Prednisone or Botox caused this reaction?