Is it rare for a leg infection to get worse while on antibiotics? also, how long does cephalexin take to work to rid of infection? 2x500mg twice a day for a large turf burn that is infected?

If the infection causing germs are sensitive to the antibiotic being used, the infection should get better with each passing day. If it is getting worse and it has not shown any improvement in one week, the antibiotic is declared ineffective. A wound culture should be obtained to find the correct bacteria causing the infection and a change to a different antibiotic should be made..

Any treated infection that does not improve on treatment should be reassessed and differential diagnoses as well as treatment have to be revised with imaging and cultures being considered.