What is the diagnosis and treatment for a patient with intermittent paresthesias (tingling) in both hands spreading into forearms and also in feet and legs bilaterally?

Bilateral Upper and Lower Extremity Paresthesias: Diagnosis and Management

The most likely diagnosis is a length-dependent peripheral polyneuropathy, and you must urgently rule out Guillain-Barré syndrome or systemic vasculitis before proceeding with evaluation for common causes like diabetic neuropathy, vitamin B12 deficiency, or other metabolic/toxic polyneuropathies. 1, 2

Immediate Red Flag Assessment

First, determine if this requires emergency evaluation:

• Rapidly progressive symptoms (developing over days) require urgent neurological consultation for possible Guillain-Barré syndrome 2, 3
• Associated motor weakness, areflexia, or dysautonomia mandate immediate evaluation 2, 3
• Ascending pattern from distal to proximal or recent infection within 6 weeks are warning signs 4
• If any red flags present, obtain urgent MRI and consider intravenous immunoglobulin or plasma exchange 1

Diagnostic Approach for Non-Emergent Cases

Clinical Pattern Recognition

The bilateral, symmetric distribution affecting both hands/forearms AND feet/legs suggests a polyneuropathy rather than mononeuropathy or radiculopathy 1, 5:

• Distal symmetric polyneuropathy typically presents with "glove and stocking" distribution 1
• Symptoms starting in feet and progressing to hands indicate length-dependent axonal neuropathy 5, 3
• Bilateral involvement suggests systemic cause (diabetes, hypothyroidism, B12 deficiency) rather than isolated nerve entrapment 4

Essential Diagnostic Workup

Perform neurophysiological studies (EMG with nerve conduction studies) to differentiate central versus peripheral causes and characterize the neuropathy type 1:

• Distinguish between axonal versus demyelinating patterns 5
• Detect small fiber neuropathy when examination is normal using intraepidermal nerve fiber density 2

Order targeted laboratory evaluation 3, 6:

• Fasting glucose and HbA1c (diabetes is the most common cause) 5, 3
• Vitamin B12 level 3
• Thyroid function tests 4
• Serum protein electrophoresis for monoclonal gammopathy 3
• Consider Lyme serology if epidemiologically appropriate 1

Reserve MRI for specific indications 1:

• Only obtain cervical/lumbar spine MRI if radiculopathy suspected (asymmetric, dermatomal pattern)
• Brain/spine MRI indicated if central causes suspected based on examination findings

Treatment Strategy

Etiology-Specific Management

For diabetic neuropathy: Optimize glycemic control as primary intervention 5, 3

For vitamin B12 deficiency: Initiate B12 supplementation 3

For inflammatory/immune-mediated neuropathy: Administer intravenous immunoglobulin or plasma exchange with monitoring for autonomic dysfunction 1

For Lyme disease: Provide appropriate antibiotic therapy if confirmed by two-tier serology 1

Symptomatic Management

Implement pain management based on neuropathic pain severity 1:

• Use gabapentinoids or tricyclic antidepressants for neuropathic pain
• Avoid opioids as first-line therapy

Promote normal movement patterns and avoid prolonged joint positioning at end range 1

Critical Pitfalls to Avoid

Do not assume bilateral carpal tunnel syndrome without EMG confirmation - while carpal tunnel is the most common mononeuropathy (5% prevalence), true bilateral involvement with lower extremity symptoms suggests polyneuropathy 5, 3

Do not delay evaluation of rapidly progressive symptoms - Guillain-Barré syndrome can progress to respiratory failure within 1-2 days 5, 3

Do not miss the 20-25% of cases that remain idiopathic after thorough workup - these are typically slowly progressive axonal polyneuropathies requiring symptomatic management 5

Follow-Up Protocol

Schedule regular monitoring visits to assess symptom progression or resolution 1:

• Monitor for development of motor weakness or autonomic dysfunction 1
• Adjust treatment based on response to interventions 1
• For chemotherapy-induced cases, consider dose modification if symptoms progress 1