Synopsis
Detect bone infection beneath a neuropathic ulcer without relying on one negative test, grade systemic and limb threat, obtain useful tissue, restore perfusion and pressure control, and choose medical or surgical treatment coherently.
- Think osteomyelitis when diabetes accompanies local infection, a deep wound or a chronic ulcer; absence of pain is expected in neuropathy and never reassures.
- Normal CRP, plain radiographs or probe-to-bone testing do not individually exclude diabetic-foot osteomyelitis under NICE NG19.
- Grade the whole threat: systemic severity, depth and extent, abscess or necrosis, perfusion, neuropathy, glucose and ketones, renal function and ability to offload.
Key red flags
Systemic inflammatory response, confusion, hypotension, tachypnoea, lactate elevation or metabolic decompensation defines severe infection and requires hospital sepsis care rather than ambulatory wound treatment.
Investigation priorities
Assess bone destruction, gas, foreign body and deformity.
Management branches
Systemic inflammatory response, metabolic decompensation, necrosis or rapidly advancing deep infection is present.
- Admit, apply sepsis care, obtain blood cultures and begin severity-appropriate intravenous antibiotics immediately.
- Call foot, orthopaedic or vascular surgery urgently and drain abscess or remove necrotic tissue without waiting for perfect imaging.
A deep ulcer suggests osteomyelitis without systemic instability or immediate necrosis.
Key medicines
Flucloxacillin for selected moderate or severe diabetic-foot infectionNICE first-choice dosing is 1 g orally four times daily or 1–2 g intravenously four times daily; combine with or without gentamicin and/or metronidazole according to severity and microbiological advice, using intravenous treatment for severe infection for at least 48 hours until stabilised.
Co-amoxiclav as a selected first-choice alternativeNICE lists 500/125 mg orally three times daily or 1.2 g intravenously three times daily, with or without gentamicin; review any intravenous therapy by 48 hours and move to an active oral regimen when clinically possible.