Endocrine Abstracts

Diabetic muscle infarction is an unusual complication of poorly controlled diabetes. It presents as an acute painful muscular swelling with difficulty in walking.

Case

A 49-year-old man with poorly controlled type 1 diabetes was admitted with a history of sudden painful swelling of the thigh. He was afebrile, with marked tender swelling and inability to extend his knee. His HbA1c 15.6%, FBC, CRP and CK were normal; autoantibodies, anticardiolipin and antiphospholipid antibodies were negative. Ultrasound showed swelling of the quadriceps of uncertain cause. MRI showed abnormal signal and minor swelling of the left vastus medialis with similar changes in other muscles, consistent with acute diabetic myonecrosis. He was managed with bed rest, analgesics and multiple insulin injections. The thigh pain improved and he was discharged home after 3 weeks.

Discussion

Spontaneous diabetic muscle infarction is an unusual complication of poorly controlled diabetes and is commonest when there are micro-vascular complications. It causes sudden non-traumatic tender swelling, 62% of cases affecting the thigh. There are seldom signs of systemic illness and although it usually resolves within few weeks, it may recur. MRI is the preferred diagnostic test, revealing swollen and oedematous muscle. Histology shows haemorrhagic muscle necrosis and oedema, with loss of normal muscle architecture. The pathogenesis is not clear but thought to be ischaemic muscle damage due to underlying small vessel disease. This leads to muscle oedema as part of hypoxia-reperfusion injury and thus, mimics a compartment syndrome. Management consist of diabetic control, analgesia, physiotherapy and rehabilitation are useful and total recovery will be expected over 4-6 weeks.

Conclusion

Diabetic myonecrosis is rare, but should be included in the differential diagnosis of acute painful swelling of the legs in diabetic patients. The differential diagnosis is wide, but includes deep venous thrombosis, necrotizing fasciitis, haematoma, Recognition of this condition avoid unnecessary surgical intervention.