What causes a sensation of feeling like cotton is stuck under the toes, particularly in individuals with diabetes or at risk of neuropathy?

Sensation of Cotton Stuck Under Toes

This sensation is a classic symptom of diabetic peripheral neuropathy, specifically indicating small fiber nerve dysfunction that causes abnormal tactile sensations (dysesthesia), and requires immediate screening with 10-g monofilament testing to assess for loss of protective sensation that predicts ulcer and amputation risk. 1

Understanding the Symptom

The "cotton stuck under toes" sensation represents dysesthesia—an abnormal, unpleasant tactile perception caused by small fiber nerve damage in diabetic peripheral neuropathy. 1, 2 This symptom pattern indicates:

• Small fiber involvement causing altered tactile sensation, burning, and tingling as the earliest manifestation of diabetic neuropathy 1, 3
• Loss of normal sensory discrimination where the brain misinterprets normal contact with surfaces as foreign material 1
• Progressive nerve dysfunction that may advance to complete numbness and loss of protective sensation if untreated 1, 4

Up to 50% of diabetic peripheral neuropathy cases are asymptomatic despite significant nerve damage, making this symptomatic presentation an important warning sign requiring immediate evaluation. 1, 4

Immediate Assessment Required

Neuropathy Screening

Perform these specific tests to confirm diagnosis and assess severity:

• 10-g monofilament testing at multiple plantar sites (hallux, first/third/fifth metatarsal heads) to identify loss of protective sensation 1
• 128-Hz tuning fork on bony prominences to assess vibration perception (large fiber function) 1
• Light touch with cotton wool on dorsum of foot or fingertip touch on toe tips for 1-2 seconds to assess tactile sensation 1
• Pinprick testing on dorsum of foot without penetrating skin to evaluate small fiber function 1
• Achilles tendon reflexes to assess deep tendon response 1

Foot Examination Components

Inspect with patient both lying down and standing:

• Skin assessment: callus formation, color changes, temperature, edema, maceration between toes 1, 5
• Structural deformities: hammer toes, claw toes, mallet toes, prominent metatarsal heads, limited joint mobility 1
• Pre-ulcerative signs: areas of high pressure, bony prominences, calluses that indicate ulcer risk 1
• Vascular status: palpate pedal pulses, assess capillary refill, evaluate for claudication history 1, 5
• Footwear inspection: examine inside and outside of shoes and socks for proper fit and adequacy 1

Rule Out Alternative Causes

Before attributing symptoms solely to diabetes, screen for:

• Vitamin B12 deficiency (especially if on metformin, which interferes with B12 absorption) 1, 3, 6
• Hypothyroidism with TSH testing 6
• Renal disease with creatinine and eGFR 6, 7
• Alcohol toxicity through history 1, 6
• Neurotoxic medications review 1, 6
• Chronic inflammatory demyelinating polyneuropathy if atypical features present 6, 7

Risk Stratification and Follow-Up Frequency

Assign IWGDF risk category to determine monitoring schedule:

• Category 0 (no peripheral neuropathy): Screen annually 1
• Category 1 (peripheral neuropathy present): Screen every 6 months 1
• Category 2 (neuropathy + PAD and/or foot deformity): Screen every 3-6 months 1
• Category 3 (neuropathy + history of ulcer/amputation): Screen every 1-3 months 1

Disease-Modifying Management

Glycemic Optimization

• Target HbA1c 6-7% to prevent neuropathy progression, though this will not reverse existing nerve damage 1, 3, 4
• Achieving near-normal glycemic control early in disease course effectively delays or prevents diabetic peripheral neuropathy development in type 1 diabetes 3
• For type 2 diabetes, glycemic control modestly slows progression but does not reverse neuronal loss 1, 3
• Avoid extreme blood glucose fluctuations, as erratic control intensifies neuropathic pain symptoms 3

Additional Risk Factor Management

• Blood pressure control: Hypertension is an independent risk factor for neuropathy development (OR 1.58), and intensive BP intervention decreases cardiovascular autonomic neuropathy risk by 25% 3
• Lipid management: Dyslipidemia contributes to neuropathy progression in type 2 diabetes 1, 3
• Weight loss: Lifestyle intervention focused on dietary weight loss improves neuropathy symptoms 3

Symptomatic Pain Management (If Painful Dysesthesia Present)

First-Line Pharmacotherapy

Choose one of these FDA-approved options:

• Pregabalin 300-600 mg/day divided into 2-3 doses (start 75 mg twice daily, titrate to 150-300 mg twice daily based on response; NNT 4.04-5.99) 1, 3, 4
• Duloxetine 60-120 mg/day once daily (NNT 4.9-5.2; avoid in hepatic disease) 1, 3, 4
• Gabapentin 900-3600 mg/day in divided doses 1, 3, 4
• Amitriptyline 25-75 mg/day at bedtime (avoid in patients ≥65 years, glaucoma, orthostatic hypotension, or cardiovascular disease) 3, 4

Second-Line Options (If First-Line Inadequate)

• Nortriptyline or imipramine 25-75 mg/day 4
• Venlafaxine 4
• Topical lidocaine or capsaicin 4
• Sodium channel blockers (lamotrigine, carbamazepine) when first-line agents fail 3

Avoid opioids including tramadol and tapentadol due to addiction risk and lack of long-term efficacy evidence. 3, 4

Critical Foot Protection Education

Provide structured, repeated education covering:

• Never walk barefoot, in socks without shoes, or in thin-soled slippers indoors or outdoors 1
• Daily foot inspection using a mirror if necessary to check for redness, warmth, breaks in skin, or any abnormalities 1, 5
• Daily foot washing with warm water, careful drying (especially between toes), and application of emollients to dry skin 1, 5
• Cut toenails straight across to prevent ingrown toenails 5
• Immediately contact healthcare provider with presence or suspicion of any pre-ulcerative lesion 1

Therapeutic Footwear Prescription

For patients with loss of protective sensation and structural abnormalities:

• Prescribe therapeutic footwear with demonstrated plantar pressure-relieving effect (30% relief compared with standard footwear) 1
• Custom-molded insoles for patients with foot deformities 1
• Extra-wide or extra-depth shoes for bony deformities 5
• Encourage consistent wearing of prescribed footwear to prevent ulceration 1

Callus Management and Podiatry Referral

• Immediate callus debridement if callus formation present with underlying neuropathy 5
• Regular debridement appointments every 4-8 weeks to prevent ulcer development 5
• Podiatry referral for ongoing preventive care and lifelong surveillance in high-risk patients 3, 5

Referral Indications

Refer to neurology or pain specialist when:

• Pain remains inadequately controlled after trials of at least two first-line medications at therapeutic doses 3
• Clinical features are atypical for diabetic neuropathy 1, 3
• Diagnosis is unclear and electrophysiological testing needed to exclude other causes 1, 3

Common Pitfalls to Avoid

• Do not assume symptoms are benign even if painless—up to 50% of neuropathy is asymptomatic but still increases ulcer risk 1, 4
• Do not neglect vitamin B12 screening especially in patients on metformin 1, 3, 6
• Do not perform routine nail care on high-risk patients without specialized training—refer to podiatry 5
• Do not assume adequate circulation based on appearance alone—measure ankle-brachial index if pulses diminished 5, 8
• Do not prescribe opioids for chronic neuropathic pain management 3, 4