Diabetic muscle infarction in patients on dialysis.
Spontaneous muscle infarction in diabetic patients is a rare condition that usually occurs in those with advanced diabetic complications. There is a high prevalence of diabetic nephropathy and varying degrees of renal failure. Both type 1 and type 2 diabetics are at risk. The mean age at presentation is approximately 40 years, and both sexes are affected. The cause is uncertain but appears to be attributable to diabetic microangiopathy, with thickening of walls of small arteries and fibrinoid occlusion. There is necrosis of all elements of the muscle, with polymorphonuclear or mononuclear cellular infiltration and a varying but often limited degree of regeneration, depending on the age of the lesion. The presentation is usually acute, with pain and swelling localized to the thigh in most instances. Systemic signs such as pyrexia are infrequent. Laboratory tests (such as white cell count and creatinine kinase) and plain radiographs are not helpful, although the erythrocyte sedimentation rate is often elevated. The diagnosis, in the appropriate setting, is strongly suggested by magnetic resonance imaging, which shows increased signal intensity and asymmetry of the muscle on T2-weighted scanning as well as fluid in the tissue planes. Management consists of resting the muscle, analgesics, and gradual mobilization. Recurrence is common and may be seen in more than 50% of the patients.