A 50 year-old-female presented with severe right thigh pain which was getting progressively worse over 2 weeks. She had no history of fever, chills, trauma, travel or recent immobilization. Patient had a longstanding history of hypertension, poorly controlled diabetes type 2 and asthma. On exam, right anterior thigh was swollen, extremely tender to palpation and warm. No involvement of either joints was noted. Except creatinine of 1.7 mg/dl (0.6-1.1mg/dl), ESR of 42 mm/hr (0-29mm/hr) and HBa1c of 11%, all other labs were normal, including CK and D-dimer. White count was normal and blood cultures had no growth. No fractures or gas in tissues were noted on X-rays. Duplex venous ultrasound was negative. On MRI T2 sequence, findings suggestive of right vastus muscle diffuse edema and swelling were noted. Diagnosis of Diabetic myonecrosis was made, given the longstanding history of uncontrolled diabetes melitus and positive MRI findings. Patient was treated conservatively with rest and symptom support. Aspirin was also started, and was discharged on a modified insulin regimen for tighter blood glucose control with home healthcare supervision. On follow up, patient reported improvement of symptoms in about 4 to 5 weeks.
Discussion: Diabetic myonecrosis is a rare complication of uncontrolled diabetes. It manifests as spontaneous infarction of a group of muscles, most commonly involving the anterior compartment of the thigh. Patients present with acute to subacute symptoms of muscle pain, swelling and occasionally low grade fevers. On literature review, no single lab finding has demonstrated any value in diagnosis. CK, ESR, white count are not significantly elevated. MRI demonstration of high intensity signal on T2 sequence has been the investigation of choice. Muscle Biopsy usually shows necrosis of the involved muscles, however is not required for diagnosis, unless MRI is inconclusive or could not be obtained. Differentials include Necrotizing fasciitis, Gas gangrene, Cellulitis, DVT and Hematomas. Treatment is mostly conservative management with rest and pain control. Starting an antiplatelet agent like aspirin has shown to have positive effect on short term prognosis. Aggressive approach with surgical debridement has shown to be associated with longer recovery times and increased morbidity. Diabetic muscle infarction should be kept in mind while working up diabteic patients for muscle pain or swelling to avert complications from invasive testing and surgical interventions which have not proven to be beneficial.
Conclusions: Awareness of this less frequently encountered acute complication of Diabetes Mellitus is important to make a diagnosis and prevent unnecessary aggressive treatments which result in poor outcomes and significant morbidity.