What is the cause and treatment of burning and tingling sensations in the ankles of an adult with no specified medical history?

Burning and Tingling in Ankles: Diabetic Peripheral Neuropathy Until Proven Otherwise

Burning and tingling sensations in the ankles are classic symptoms of diabetic peripheral neuropathy (small fiber dysfunction), and you must immediately screen for diabetes with fasting blood glucose, assess for other treatable causes (vitamin B12 deficiency, hypothyroidism), and initiate first-line neuropathic pain management with pregabalin, duloxetine, or gabapentin if pain is present. 1, 2

Immediate Diagnostic Approach

Screen for Diabetes First

• Check fasting blood glucose or HbA1c immediately - diabetes is the most common cause of peripheral neuropathy, affecting over 50% of cases in Western populations, and burning/tingling are hallmark symptoms of diabetic small fiber neuropathy 3, 4
• The American Diabetes Association confirms that burning pain and dysesthesias (unpleasant sensations of burning and tingling) are the most common early symptoms of diabetic peripheral neuropathy, caused by small fiber involvement 1
• These symptoms typically start distally in the toes and feet with gradual ascending progression 5

Rule Out Other Treatable Causes

Diabetic neuropathy is a diagnosis of exclusion - you must evaluate for: 1, 2

• Vitamin B12 deficiency (especially if patient takes metformin) - check serum B12 with methylmalonic acid 3, 4
• Hypothyroidism - check thyroid-stimulating hormone 4, 6
• Monoclonal gammopathies - serum protein electrophoresis with immunofixation 3, 4
• Neurotoxic medications - chemotherapy agents (cisplatin, paclitaxel, vincristine), amiodarone, HIV medications 1, 3
• Alcohol abuse - obtain detailed history 1, 4
• Renal disease - comprehensive metabolic profile 4, 6

Perform Focused Neurologic Examination

Confirm small and large fiber dysfunction: 1, 2

• Small fiber function: Test pinprick sensation and temperature sensation starting at the dorsal aspect of the hallux and moving proximally 1
• Large fiber function: Test vibration perception with 128-Hz tuning fork and assess ankle reflexes 1
• Protective sensation: Perform 10-g monofilament testing to identify feet at risk for ulceration 1
• Document bilateral and symmetric involvement, which is the hallmark of typical diabetic neuropathy 5

Treatment Algorithm

If Diabetes is Confirmed

Optimize glycemic control immediately - this is the only strategy convincingly shown to prevent or delay diabetic peripheral neuropathy progression, though it does not reverse existing neuronal loss 1

Manage cardiovascular risk factors aggressively - control blood pressure and lipids to slow neuropathy progression in type 2 diabetes 1, 2

Initiate Pharmacologic Pain Management

Start first-line neuropathic pain medication immediately if burning/tingling is bothersome: 2, 3

• Pregabalin (α2-δ calcium channel ligand) - first-line option 2, 3
• Duloxetine (serotonin-norepinephrine reuptake inhibitor) - first-line option 2, 3
• Gabapentin (α2-δ calcium channel ligand) - first-line option; 38% of patients achieve at least 50% pain reduction at 1200 mg daily 2, 3

Alternative options include: 1

• Tricyclic antidepressants (amitriptyline, nortriptyline) 3
• Anticonvulsants (valproate, carbamazepine) 1
• Opioids (tramadol, oxycodone) for refractory cases 1

Combination drug therapies may provide added benefit when monotherapy is insufficient 3

Critical Preventive Foot Care

Up to 50% of diabetic peripheral neuropathy is asymptomatic, making prevention essential: 1, 7

• Educate on daily foot inspection for cuts, blisters, or pressure areas 2
• Recommend protective footwear with adequate cushioning and proper fit 2
• Arrange podiatry referral for regular foot care 2
• Perform annual 10-g monofilament testing to monitor progression and identify feet at risk for ulceration and amputation 1, 7

Screen for Autonomic Neuropathy

Assess for autonomic symptoms annually: 1, 5

• Cardiovascular: Resting tachycardia (>100 bpm), orthostatic hypotension (systolic drop >20 mmHg or diastolic drop >10 mmHg without appropriate heart rate increase) 1, 5
• Gastrointestinal: Gastroparesis, constipation, diarrhea, fecal incontinence 1, 5
• Genitourinary: Erectile dysfunction, sexual dysfunction, bladder dysfunction (nocturia, urinary incontinence) 1, 5
• Sudomotor: Increased or decreased sweating, dry cracked skin 5

Common Pitfalls to Avoid

• Do not prescribe nitrofurantoin for urinary tract infections in diabetic patients - it significantly increases neuropathy risk 2
• Do not rapidly lower HbA1c if severely elevated - this can paradoxically worsen neuropathic symptoms (treatment-induced neuropathy) 2
• Do not delay treatment waiting for electrodiagnostic studies - these are rarely needed except when clinical features are atypical or diagnosis is unclear 1
• Do not overlook vitamin B12 deficiency, especially in patients taking metformin, as deficiency compounds neuropathy risk 2, 3

When to Refer to Neurology

Refer for electrodiagnostic studies or specialist evaluation only when: 1

• Clinical features are atypical (asymmetric, rapid progression, predominantly motor involvement)
• Diagnosis remains unclear after initial workup
• Severe or refractory symptoms despite appropriate management
• Suspicion for chronic inflammatory demyelinating neuropathy, vasculitis, or inherited neuropathies 1