An unusual cause of foot ulcer in a patient with diabetes mellitus

Abstract

A diabetic foot ulcer is the leading cause of nontraumatic amputation worldwide. The most important predisposing factor for diabetic foot ulcer is peripheral neuropathy. Rat bites are an uncommon but important cause of ulcer in patients with diabetes, especially in lower socioeconomic strata. A 56-year-old male from southern India, a known patient with type 2 diabetes for the past 15 years with severe peripheral neuropathy, presented to our center with multiple bite marks on bilateral feet and destroyed nails. He was initially managed with local measures and injection tetanus toxoid; however, he rapidly worsened over the next 5 days to develop bilateral cellulitis of the feet and right great toe osteomyelitis. His biochemistry showed uncontrolled diabetes (HbA1c: 9.9) and radiology confirmed right great toe osteomyelitis. He underwent transmetatarsal amputation of the right first toe along with intravenous antibiotics followed by oral antibiotics (amoxicillin with clavulanic acid) for a total duration of 6 weeks and optimization of glycemic control. He improved completely over the next 1 month. Rat bites are a rare but readily preventable cause of foot ulcer in diabetic patients. Primary care and family physician play a vital role in educating patients about preventive aspects such as avoidance of using vegetable oil as a moisturizer that may attract rodents and insects.

Keywords: Diabetic foot ulcer; peripheral neuropathy; rat bite.