How long should an allergic reaction symptom to an antibiotic last?

I was put on Ciprofolxacin for an infection and had an allergic reaction. I started taking it on dec 19th and stopped 3 days later when I realized that the spots on my arms weren't a flare-up of psoriasis, but an allergic reaction. The rash has gotten steadily worse since then instead of better. It's been about 11 days since I stopped taking it, Shouldn't the symptoms be lessening by now?