Introduction

Diabetic peripheral neuropathy (DPN) is the most common chronic complication of diabetes mellitus and results from long-term hyperglycaemia causing metabolic and microvascular damage to peripheral nerves.It usually presents as distal symmetric polyneuropathy, affecting the feet first and progressing proximally in a stocking–glove distribution.

All patients should be screened for distal symmetric polyneuropathy at the time of diagnosis of type 2 diabetes mellitus and at least annually thereafter, because early detection prevents foot ulceration and amputation.

Risk Factors

• Long duration of diabetes

• Poor glycaemic control (high HbA1c)

• Older age

• Smoking

• Alcohol use

• Hypertension

• Dyslipidaemia

• Obesity

• Chronic kidney disease

• Vitamin B12 deficiency (especially in metformin users)

• Previous diabetic foot ulcer

• Sedentary lifestyle

Signs and Symptoms

Sensory symptoms (most common)

• Burning feet (especially at night)

• Tingling / prickling sensations

• Electric shock-like pain

• Numbness

• Reduced temperature sensation

• Allodynia (pain from light touch)

Motor involvement (late)

• Weakness of intrinsic foot muscles

• Claw toes

• Foot deformities

• Unsteady gait

Autonomic features (may coexist)

• Dry cracked skin

• Reduced sweating

• Warm foot due to arteriovenous shunting

Diagnostic Criteria

Suggestive features include:

• Unsteady gait

• Burning, aching pain or tenderness in legs or feet (at rest or night)

• Prickling sensations distal > proximal (stocking-glove distribution)

• Numbness distal > proximal

• Loss of protective sensation

• Previous foot ulceration or amputation

Diagnosis is clinical and supported by abnormal neurological examination.

Investigations

Bedside screening (essential)

• Pressure sensation — 10 g monofilament

• Light touch — cotton wool

• Vibration — 128 Hz tuning fork

• Temperature sensation

• Ankle reflexes

• Postural hypotension

• Peripheral pulses (posterior tibial & dorsalis pedis)

• Foot inspection for deformity or ulcer

Additional tests (if atypical)

• HbA1c

• Vitamin B12 level

• Renal function tests

• Nerve conduction studies (if diagnosis uncertain)

Management

Goals:

1. Relieve pain

2. Prevent ulceration

3. Prevent amputation

4. Improve quality of life

Non-Pharmacological

• Strict glycaemic control (HbA1c target ≈ <7%)

• Daily foot inspection

• Proper footwear (wide, soft, closed shoes)

• Avoid walking barefoot

• Smoking cessation

• Regular exercise

• Weight reduction

• Treat calluses early

• Regular podiatry review

• Patient education on foot care

Pharmacological

Painful neuropathy treatment

Burning pain — Antidepressants

• Amitriptyline: 25–150 mg at nightOR

• Imipramine: 50–150 mg/day

Lancinating / shooting pain — Anticonvulsants

• Carbamazepine: 400–800 mg/dayOR

• Sodium valproate: 10–15 mg/kg/day

(Modern alternatives if available: gabapentin, pregabalin, duloxetine)

Foot protection

• Treat fungal infections

• Moisturizing creams (avoid between toes)

• Manage ulcers early

• Antibiotics if infected ulcer

Prevention

• Annual neuropathy screening in all diabetics

• Tight glucose control from diagnosis

• Proper footwear education

• Routine foot examination at every clinic visit

• Avoid smoking and alcohol

• Early treatment of callus and minor injuries

• Patient self-inspection daily