If there is concern about an infection, an antibiotic should certainly be prescribed. X-rays are not normally needed to make the diagnosis of a skin infection, unless it is so severe that you are worried about it spreading to the bone. If there has not been an injury to the ankly (i.e. twisting, falling or spraining), then I would pursue the infection route. Also, if there is a break in the skin (i.e. a cut or ulcer), then the risk of infection would increase.
The other reason one may do an X-ray would be to diagnose a fracture - which also can cause your symptoms.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b
I'm 42, male, 6'6" and ~230 lbs. no heart problems previously detected, tall, have some pot-belly but not much overweight, spend extensive hours by a computer for the last 10 years. Rarely excercise.
But I suspect could this be an infection of a kneecaused
P.S I'm sorry I can not help the above person, because I'm not a doctor, but I express my sympathy to them and I'd like to know Doctor's opinion. I think if knee swelling moves to an ankle and a foot that could be water accumulation from a heart problem (I hope not!) same as it happened to my mother who died before becoming 60. She used to complain that her feet are swelling a lot. I'd suggest stop eating salt and any fat foods, only eat vegetables, oats and take fish oil. Don't eat eggs or anything having cholesterol, trans-fats and saturated fats. But this is just my guess.