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Diabetic foot ulcer

A diabetic foot ulcer is neuropathic, ischaemic or mixed; treatment rests on four pillars — offloading, debridement and wound care, infection control and revascularisation when there is ischaemia — and every patient needs a blood-flow assessment, because ABI in diabetes may mislead; a toe pressure below 30 mmHg requires urgent vascular work-up.

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Why it matters in the exam

A neuropathic ulcer lies at pressure points of the foot (metatarsal heads, heel), with callus around it, in a warm foot with palpable pulses and loss of sensation; an ischaemic ulcer lies at the toe tips and foot margins, is painful (unless neuropathy is severe), in a cold foot without pulses. Most patients have a mix. On flow assessment: ABI may be falsely high because of calcified arteries, so toe pressure and the toe-brachial index are measured (TBI below 0.7 is abnormal). According to IWGDF 2023, a toe pressure below 30 mmHg or TcPO2 below 25 mmHg requires urgent imaging and consideration of revascularisation; an ulcer not improving after 4–6 weeks of good care also requires vascular work-up.

Infection is diagnosed clinically (redness, local warmth, swelling, pain, purulent discharge) and graded by IWGDF/IDSA — mild, moderate or severe (with systemic signs). A positive probe-to-bone test, together with a high ESR (above 70 mm per hour), suggests osteomyelitis; a plain X-ray is taken and then MRI. An ulcer without infection is not treated with antibiotics. Mild infection is treated with oral antibiotics for 1–2 weeks; deep infection with an abscess, gas or necrosis needs urgent surgical drainage — "time is tissue"; osteomyelitis is treated with antibiotics for about 6 weeks, or a shorter course after resection of infected bone. Offloading is mandatory for a neuropathic plantar ulcer: the best device is a non-removable knee-high cast (total contact cast), because a removable boot is not always worn. Glucose control, smoking cessation, and fitted footwear to prevent recurrence.

A multidisciplinary team — vascular surgeon, endocrinologist, orthopaedic surgeon, wound specialist and orthotist — reduces amputations, so referral is early.

Key points

• Four pillars: pressure, wound, infection, flow.
• Toe pressure below 30 mmHg — urgent work-up.
• Deep infection — urgent drainage.
• Probe-to-bone and high ESR — osteomyelitis.
• Non-removable cast for a neuropathic ulcer.

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Sources

• IWGDF Guidelines on the prevention and management of diabetes-related foot disease, 2023 — Classification, PAD, infection and offloading
• IWGDF/IDSA Guidelines on the diagnosis and treatment of diabetes-related foot infections, 2023 — Recommendations
• Global Vascular Guidelines on the management of chronic limb-threatening ischemia (SVS/ESVS/WFVS), 2019 — Diabetic foot and WIfI

Sources are given for further reading; the text is written afresh and not copied from them.

Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.