On the right is the x ray of the left shin of an 83 year old man who presented with a red, hot, swollen, tender left shin. The appearances were consistent with cellulitis, but he responded only slightly to antibiotics. X ray examination, raised alkaline phosphatase concentration, and the clinical picture confirmed the diagnosis of Paget's disease (osteitis deformans). His pain improved after treatment with bisphosphonates was started. Common in older people, Paget's disease can lead to painful, deformed, and fragile bones (the x ray shows anterior cortical fractures). Hyperaemia causes the reddening of the overlying skin.
