Bone infection. Coloured X-ray of a foot showing osteitis (bone inflammation) of the second toe in a diabetic patient. The phalanges (toe bones) have lost much of their structure. A bony growth (centre left) is also seen on the metatarsal bone connected to the big toe. Osteitis is usually caused by a bacterial infection (osteomyelitis). It causes severe pain in the affected bone, a fever and swelling over the affected area. If antibiotic treatment does not clear up the infection, the affected bones must be removed surgically. Other causes of osteitis include Paget's disease and hyperparathyroidism, overactivity of the parathyroid glands.