Synopsis
Diagnose diabetic foot infection clinically, grade limb and systemic threat, obtain deep microbiology and coordinate debridement, perfusion restoration, offloading and antimicrobial treatment.
- Diabetic foot infection is a clinical diagnosis: purulence or at least two local inflammatory features must be attributed to infection, not culture alone.
- Do not give antibiotics to an uninfected ulcer; colonisation is expected and treatment does not promote healing.
- Remove dressings, inspect between toes and examine depth, undermining, necrosis, fluctuance, deformity, sensation and perfusion.
Key red flags
Hypotension, confusion, tachypnoea, lactate rise or oliguria indicates severe infection with organ dysfunction.
Erythema extending more widely, lymphangitis, abscess, gangrene or involvement of tendon, muscle, joint or bone requires urgent multidisciplinary assessment.
Investigation priorities
Define ulcer size, depth, undermining, exposed structures, drainage and viable versus necrotic tissue.
Management branches
A person with diabetes has a new ulcer, drainage, redness, swelling or unexplained metabolic deterioration.
- Use ABCDE when systemically unwell, remove all dressings and inspect both feet, interdigital spaces, footwear and the entire affected limb.
- Clean and debride enough to assess ulcer depth, purulence, necrosis, fluctuance, exposed tendon or bone, sensation and deformity.
Key medicines
Flucloxacillin for mild infectionGive 500 mg to 1 g orally four times daily for seven days for mild diabetic foot infection, with further duration only after clinical review.
Clarithromycin allergy alternativeGive 500 mg orally twice daily for seven days when penicillin allergy makes flucloxacillin unsuitable and local guidance supports macrolide activity.