Investigations for Tingling in Both Feet

Initial Evaluation

The American Diabetes Association recommends a comprehensive neurological assessment, including a 10-g monofilament test, vibration testing with a 128-Hz tuning fork, pinprick sensation testing, and ankle reflex assessment to identify loss of protective sensation (LOPS) in patients with diabetes 1, 2, 3
A detailed history of the tingling symptoms, including onset, progression, exacerbating factors, and associated symptoms, should be obtained from the patient 3
The patient should be assessed for pain using a simple pain scale and the characteristics of the symptoms (numbness, burning, etc.) should be documented 4, 3
The patient's risk factors and potential causes of tingling, such as diabetes mellitus, vitamin B12 deficiency, thyroid dysfunction, history of chemotherapy, alcohol use, and HIV, hepatitis B and C, should be evaluated 1, 3, 4

A comprehensive neurological examination should be performed, focusing on 10-g monofilament testing, vibration testing, pinprick sensation testing, and ankle reflex assessment 2, 1, 3
The American College of Cardiology recommends a vascular examination, including palpation of lower extremity pulses, auscultation for femoral bruits, and assessment of capillary refill time 5, 6
The feet should be inspected for skin integrity, ulcers, or wounds, deformities, calluses, or areas of increased pressure 1, 6

Fasting blood glucose and hemoglobin A1c should be tested to assess for diabetes 3
A complete blood count should be performed to evaluate for anemia 4
Thyroid function tests (TSH, free T4) should be conducted to assess for thyroid dysfunction 4, 3
Vitamin B12 level should be tested to evaluate for vitamin B12 deficiency 3

The American College of Cardiology recommends an Ankle-Brachial Index (ABI) if peripheral arterial disease is suspected 5
Exercise treadmill ABI testing should be considered if resting ABIs are normal or borderline but symptoms suggest peripheral arterial disease 5
Toe-Brachial Index (TBI) should be tested if ABI >1.40 (non-compressible arteries) 5

The American Diabetes Association recommends referral to endocrinology for diabetes management 1, 3
Referral to vascular surgery should be considered for significant peripheral arterial disease 5
Referral to podiatry should be considered for foot care and management of foot deformities 1, 2

Failing to perform a complete foot examination in patients with diabetes (should be done at least annually) 1, 6
Relying on a single test for diagnosing peripheral neuropathy (at least two tests should be performed) 1, 3
Not considering non-diabetic causes of peripheral neuropathy in patients with diabetes 3
Overlooking the need for vascular assessment in patients with neuropathic symptoms 5
Failing to educate patients with LOPS about proper foot care and daily foot inspection 1, 2