Differentials
| Presenting Feature | What might it be? | What might I find? | |
| Foot Ulcer |
Neuropathic ulcer |
Common in patients with known neuropathy e.g., diabetes.
Poor sensation so unaware of injury/friction to feet. Located at pressure points on foot e.g., heel. Painless, peripheral. Foot will be well perfused unless concurrent PAD. |
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Arterial ulcer |
Risk factors: smoking, alcohol, low exercise, obesity, stress.
May have PAD symptoms e.g., claudication, weak pulses. Arise distally, peripheral circulation poor: toes, dorsal foot. Small, painful, punched out, well demarcated, deep, pale. Pain worse on elevation of leg due to poor arterial supply. |
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Venous ulcer |
Associated with chronic venous skin changes e.g., Eczema.
Arise in gaiter region just above the ankle/below calf. Larger, less painful, irregular edges, superficial, bleeding. Pain improved with leg elevation: relief of venous pressure. |
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| Foot Deformity |
Toe deformities |
Combined sensorimotor neuropathy→foot muscle weakness→deformity.
Deformity then causes abnormal pressure, predisposing to ulceration. Claw toe – extension at MTPJ with flexion at PIPJ and DIPJ. Hammer toe – extension at MTPJ, flexion at PIPJ and extension at DIPJ. Hallux valgus – medial deviation of great toe, ↑prominence of MTPJ. |
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Pes cavus |
Combined sensorimotor neuropathy→foot muscle weakness→deformity. Commonly seen with claw toes. Development of high foot arch.
Increased prominence and pressure on metatarsal heads. |
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Charcot arthropathy |
Significant diabetic complication – fracture and joint destruction secondary to trauma un-noticed by the patient due to ↓sensation.
Continued weight bearing perpetuates trauma and inflammation. Hot, swollen foot, often no pain reported, rocker-bottom deformity. |
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| Foot Pain |
Diabetic neuropathy |
Uncontrolled diabetes→sensorimotor peripheral neuropathy.
Symptoms include loss of sensation and co-ordination, tingling, pain. Reduced sensation on monofilament examination, high stepping or ataxic gait. |
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Peripheral arterial disease |
Uncontrolled diabetes→vascular damage and peripheral arterial disease.
Ischaemia to feet→claudication, ulceration, poor healing, gangrene. Pale, cool foot, reduced hair growth, weak or absent foot pulses, prolonged CRT. |
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| Foot Infection |
Cellulitis |
Infection of the skin, diabetes ↑infection risk and reduces healing.
Acute unilateral redness, swelling, heat, pain to skin of lower leg or foot. May be associated with systemic upset e.g., pyrexia. |
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Osteomyelitis |
Infection of bone, diabetes ↑infection risk and ↓ blood flow to bone.
Symptoms similar to cellulitis, ↑suspicion if ulceration and visible exposed bone. Usually secondary to foot ulcer infection. ↑risk of amputation. |
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Checklist
| Preparation | Wash – Name – Explain | |
| Position patient standing initially | ||
| Expose feet | ||
| General Inspection | Gait | |
| Position the patient reclining on couch | ||
| Body habitus | ||
| Walking aids | ||
| Examination of footwear | ||
| Presence of all digits | ||
| Gross deformity to foot | ||
| Clues in bed space | ||
| Closer Inspection | Deformity | |
| Colour | ||
| Hair distribution | ||
| Broken skin | ||
| Callus | ||
| Ulcers | ||
| Nails | ||
| Palpation | Temperature | |
| Capillary refill | ||
| Dorsalis pedis pulse | ||
| Posterior tibial pulse | ||
| Sensation to great toe | ||
| Sensation to middle toe | ||
| Sensation to little toe | ||
| Sensation to 1st metatarsal head | ||
| Finishing | Re-cover patient | |
| Wash hands |
Explanation
Preparation
“I have been asked to carry out a diabetic foot examination. This involves looking at your feet and then checking the sensation and pulses. You can ask me to stop at any time. Are you happy for me to do that?”
Position the patient in a standing position initially. Ask the patient to expose their feet, making sure that shoes, socks, and dressings are removed so that you can carry out a thorough inspection.
General Inspection
Assess gait by asking the patient to walk across the room and back. Is the patient confident and able to walk unaided? Observe the gait for any signs of peripheral neuropathy, e.g., high-stepping gait or sensory ataxia.
Reposition the patient reclining on the couch with their legs and feet outstretched.
Look at the patient and around the bed space for useful signs:
- Body habitus – obesity is a risk factor for developing type 2 diabetes and diabetic foot complications.
- Walking aids (e.g., stick, wheelchair)
- Footwear – inspect footwear for abnormal patterns of wear, e.g., asymmetry.
- Presence of all digits – missing digits suggests prior amputation.
- Gross foot deformity (e.g., Charcot foot, pes planus)
- Clues around the bed space (e.g., medications, cigarettes)
Closer Inspection
Examine both feet together, noting:
- Deformity (e.g., hammer toe, claw toe, hallux valgus, rocker-bottom foot)
- Colour – pallor is present in peripheral arterial disease, whereas red and inflamed skin may indicate infection.
- Hair distribution – reduced hair growth in peripheral arterial disease.
- Broken skin
- Callus – abnormal pressure due to deformity causes callus build-up, which predisposes to ulcer formation.
- Ulcers
- Nails (e.g., length, hygiene, evidence of infection such as onychomycosis or paronychia)
Ensure the feet are examined thoroughly including between the toes and under the heels.
If a foot ulcer is present, evaluate the size, shape, depth, borders, location, and whether the ulcer is painful to determine if the ulcer is arterial, venous, or neuropathic in nature.
Palpation
Palpate the feet to ensure that the following are intact:
- Circulation
- Sensation
To examine circulation, assess:
- Temperature
- Capillary refill
- Dorsalis pedis pulse
- Posterior tibial pulse
The dorsalis pedis pulse is located on the dorsum of the foot, just lateral to the extensor hallucis longus tendon.
The posterior tibial pulse is located approximately halfway between the medial malleolus and the heel.
To examine sensation, ask the patient to close their eyes, and use a monofilament to demonstrate the sensation on the patient’s sternum. Touch the monofilament at 90 degrees to the patient’s skin using enough pressure to just make the monofilament start to bend.
Then use the monofilament to check sensation in each of the following areas on the sole of the foot in turn, asking the patient to say ‘yes’ when they feel the monofilament touch:
- Great toe
- Middle toe
- Little toe
- 1st metatarsal head
Additional examination steps, which no longer form part of a standard diabetic foot examination, include:
- Vibration sense
- Proprioception
- Ankle reflex
Finishing
Thank the patient and allow them to cover themselves. Wash your hands.
Depending on the examination findings, you may wish to carry out further investigations, including blood tests (e.g., capillary blood glucose or HbA1c), and further vascular assessment (e.g., Doppler or ankle-brachial pressure index).
Last updated Aug 2025
Head to members.zerotofinals.com for practice OSCE stations, including an interactive checklist, specific cases and clinical findings.
