<s>[INST] Have Cellulitus. It has been about 9 days. There is less pain but still have squishy lump area on shin. It is not real hot. Doc put me in Doxycyclene. Why would she not have put me on lower dose clindamycin ( although they gave me a 600 mg shot intially )or axithromycin or clarithromycin. I am allergic to penicillin and the abovw are substitues.. [/INST] Hello, Thank you for your queryAntibiotics are prescribed based on the type of organism that is most likely to have caused the infection and the Chat Doctor. This differs between locations and even between hospitals in the same location. Each facility has a treatment protocol. Antibiotics are prescribed based on its benefits and risks. Ideally, a culture test of the discharge from the infection or of your blood is done to identify the causative bacteria. If the infection is not subsiding and cured with the current course of antibiotic, you will need a change of antibiotics. Hope this helps. Wish you good health </s>