11/17 went to see my primary doctor for skin infection on my cheek, she put me on Cephalexin for 7 days, but my wound wasn’t healing so she put me on Amoxicillin for 6 days and the wound was infected on 12/8 so, my doctor prescribed Sulfamethoxazole 800mg / Trimethoprim 160mg (Bactrim DS) to see if it will help.

After 6 days of taking the med. my lymph node swollen, weak ,rashes ,swollen face and lips.
So i ended up in the ER on 12/16, ER Doctor said I am allergic to Sulfa based antibiotic so I stop taking it. ER doctor switched me to clindamycin 300mg for 10 days , prednisone for 4 days , Pepcid for 5 days and Benadryl 25mg every 6 hours.

I have been taking them on schedule and finished all the med by 12/23. My infection went away but left me with two closed wounds on face. I am still waiting for the wounds to heal completed at the moment.

On 12/24 , an itchy patch of rash appeared on my tummy and it repeatly growed over night till my upper body was covered by this rash and my lymph node was swollen but do not have swollen lip or face.

I went to ER on 12/25 , ER Dr. said it’s Bactrim antibiotic allergy and he did not want to give me anymore steroid , mainly wanted me to rely on Benadryl, he thinks my primary doctor over used drug on me.

Today the rash grows to both of my legs , I am wondering if this is normal for Bactrim rash to return after 12 days without expose to it ? How long will it takes for Bactrim to be out of my system?
How long will this rash last ?

Thank you all for reading my question, please help me.