Foot Care Nurse Course
Module 3: Common Foot Conditions & Diseases

Lesson 4: Ingrown & Thickened Toenails

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Module 3 · Lesson 4 — Ingrown & Thickened Toenails
Module 3 of 10 · Lesson 4 of 5
Module 3 · Lesson 4

Ingrown & Thickened Toenails

Estimated time: 25 min Pathology
Learning Objectives

By the end of this lesson, the learner will be able to:

  1. Describe the pathophysiology of ingrown toenails (onychocryptosis) and the factors that contribute to their development.
  2. Stage an ingrown toenail using the Heifetz classification and apply the staging to determine appropriate management or referral.
  3. Demonstrate proper nail trimming technique and counsel patients on prevention.
  4. Differentiate among the principal causes of nail thickening — onychomycosis, onychauxis, and onychogryphosis — and recognize when each warrants referral.
  5. Apply nursing scope considerations and special precautions for patients with diabetes, peripheral artery disease, or neuropathy.

Ingrown and thickened toenails account for a substantial share of foot care visits — and most of them stem from preventable causes: improper trimming, ill-fitting footwear, and microtrauma. This lesson covers the staging that drives ingrown toenail management, the technique that actually prevents recurrence, and how to differentiate the three principal causes of nail thickening so you know when nursing care is appropriate and when to refer.

Part 1
Ingrown Toenails (Onychocryptosis)

An ingrown toenail occurs when the lateral edge of the nail plate penetrates the surrounding nail fold tissue. The medial side of the great toenail is by far the most common site. What starts as a minor mechanical irritation can progress to inflammation, infection, and chronic granulation tissue if untreated.

Common contributing factors

  • Improper trimming — cutting too short, rounding the corners, or leaving spicules
  • Tight footwear — particularly narrow toe boxes that compress the great toe
  • Trauma — stubbing, dropped objects, athletic injuries
  • Hyperhidrosis — softens the nail and surrounding skin
  • Anatomic predisposition — congenitally curved (involuted) nails

Heifetz Staging: The Clinical Framework

Ingrown toenails progress through three predictable stages. The stage drives whether nursing management is appropriate or whether referral is needed.

1
Stage 1 · Mild
Inflammation
Findings Erythema and mild edema of the lateral nail fold. Mild tenderness. No drainage or granulation tissue.
Pain Mild — usually only on direct pressure or with shoe contact.
✓ Conservative nursing care appropriate
2
Stage 2 · Moderate
Drainage & early infection
Findings Increased erythema and edema. Serous or seropurulent drainage. Early hypertrophy of the nail fold; possible early granulation tissue.
Pain Moderate to significant; constant rather than just pressure-related.
→ Refer; partial nail avulsion often required
3
Stage 3 · Severe
Chronic granulation
Findings Marked granulation tissue and hypertrophy of the lateral nail fold. Chronic drainage. Often present for weeks or months.
Pain Significant chronic pain; impaired ambulation common.
→ Refer to podiatry for surgical management
Diabetes & vascular disease change the rules

Any stage of ingrown toenail in a patient with diabetes, peripheral artery disease, or peripheral neuropathy warrants prompt referral to podiatry — even Stage 1. The risk of progression to ulceration, deep infection, or osteomyelitis is substantially higher in this population, and what would be a routine conservative case in a healthy adult becomes an urgent referral in a high-risk patient.

Stage 1: Conservative Nursing Management

For Stage 1 ingrown toenails in otherwise healthy adults, evidence-based conservative care resolves the majority of cases.

The 5-step protocol
1
Warm soaks

10–20 minutes, 2–3 times daily, in plain warm water. The warmth softens the nail and reduces inflammation.

2
Cotton wisp or dental floss elevation

After soaking, gently lift the offending nail edge and place a small wisp of cotton or a thin piece of dental floss under it to encourage growth out of the nail fold. Replace daily.

3
Topical antibiotic ointment

If mild signs of local infection are present, a thin layer of topical antibiotic per provider direction. Watch for sensitivity.

4
Footwear modification

Wide toe-box shoes or open-toed footwear during healing. Avoid pressure on the affected toe.

5
Reassess at 1–2 weeks

If not improving — or if signs progress to Stage 2 (drainage, increased pain, granulation) — refer to podiatry for procedural management.

Prevention Starts With Technique

Most ingrown toenails are caused by improper trimming. This is the single highest-yield piece of patient education in foot care nursing.

Right way
Properly trimmed toenail A toe with the nail trimmed straight across following the natural shape of the nail bed. The corners are visible above the lateral nail folds and the free edge extends slightly past the tip of the toe. corners visible corners visible
Trim straight across or follow the natural nail contour Leave a small free edge of nail visible past the tip of the toe. Keep both corners visible above the nail folds. File any sharp edges smooth.
Common errors
Improperly trimmed toenail A toe with the nail cut too short and the corners cut into curves. The skin of the lateral nail folds has begun to grow over where the nail corners used to be, with redness suggesting an early ingrown nail. skin overgrowth skin overgrowth
Don't cut too short or round the corners Cutting the nail below the tip of the toe or rounding the lateral corners allows the nail fold skin to grow over the nail edge. The nail then has nowhere to grow but into the skin.
The teaching line that works

"Trim straight across, leave the corners visible, file the rough edges smooth." Three short sentences that fit on a refrigerator magnet — and prevent more ingrown nails than any procedure does.

Part 2
Thickened Toenails

Not every thickened toenail is fungal. Three distinct conditions present with thickening, and the management of each differs. Knowing the differential is what allows nurses to give patients the right answer when they ask "is this a fungus?" — and to direct care appropriately.

The differential

Feature
Onychomycosis
Onychauxis
Onychogryphosis
Cause
Fungal infection
Repetitive microtrauma, aging
Chronic neglect, severe trauma
Color
Yellow-brown, white streaks
Normal or slightly yellow
Yellow-brown, often dark
Shape
Thick, brittle, crumbling
Thick but normal contour
Thick, curved ("ram's horn")
Subungual debris
Yes, often prominent
Minimal
Variable
Confirms diagnosis
KOH, culture, PCR
Clinical (rule out fungus)
Clinical (severe deformity)
Why this differential matters

Onychomycosis may benefit from oral antifungal therapy (covered in Lesson 1). Onychauxis won't respond to antifungals — it needs mechanical management (filing, conservative debridement, footwear correction). Onychogryphosis usually requires podiatry-led care because the deformity is beyond what can be managed in routine nursing visits.

Conservative Nursing Management

For onychauxis without active fungal infection, mechanical reduction is the mainstay. The goal is patient comfort and footwear fit — not restoration of the original nail (which is rarely possible).

Approach to thinning a thick nail
1
Inspect first

Examine the nail and surrounding skin for color changes, drainage, or signs of infection. Photograph or document baseline appearance.

2
Reduce length conservatively

Use heavy-duty nail nippers in small bites, following the natural contour of the nail. Stop frequently to reassess.

3
Reduce thickness

Use a manual file or, where scope and credentialing permit, a rotary tool to gradually thin the nail plate. Multiple visits are often required — never thin to a level that compromises nail integrity.

4
Inspect the nail bed

After debridement, check the nail bed for any signs of breakdown, ulceration, or sub-nail tissue damage. This is especially important in patients with diabetes.

5
Schedule maintenance

Thickening recurs. Regular maintenance visits (typically every 6–12 weeks) prevent the nail from becoming unmanageable again.

Tools for thickened nail care

Heavy-duty nippers
For length reduction
Manual nail file
Thickness reduction; smoothing
Rotary tool (Dremel)
Faster thinning, where credentialed
Diabetes & high-risk feet

For patients with diabetes, peripheral artery disease, or neuropathy, thickened nails require extra caution. Inspect carefully for sub-nail ulceration before and after debridement, document thoroughly, and consider podiatry-led care when scope or risk is in doubt. A dropped nipper or aggressive thinning can create a wound that does not heal.

Patient Teaching Moment

A 38-year-old runner presents with a painful, red, swollen lateral nail fold of the right great toe. No drainage. Pain mild, only when wearing closed shoes. Stage 1 ingrown nail, otherwise healthy. The nurse demonstrates the cotton-wisp technique, recommends warm soaks twice daily, advises wide toe-box footwear during healing, and counsels: "Trim straight across, leave the corners visible, file the rough edges smooth." Reassessment at 10 days; if not improving or progressing to drainage, refer to podiatry. Resolves uneventfully.

Ready to check your understanding? Take the quick knowledge check for this lesson.

Educational Disclaimer

The information on this website and any communication with RNscrub Foot Care is provided for educational and informational purposes only. It is not a substitute for medical advice, diagnosis, or treatment. Patients are always encouraged to consult with their primary care provider or appropriate specialist for individual clinical decisions.

References

  1. Heifetz CJ. Ingrown toenail: a clinical study. American Journal of Surgery. 1937;38:298–315.
  2. Mayeaux EJ Jr, Carter C, Murphy TE. Ingrown Toenail Management. American Family Physician. 2019;100(3):158–164.
  3. Eekhof JAH, Van Wijk B, Knuistingh Neven A, van der Wouden JC. Interventions for ingrowing toenails. Cochrane Database of Systematic Reviews. 2012;CD001541.
  4. Singh G, Haneef NS, Uday A. Nail changes and disorders among the elderly. Indian Journal of Dermatology, Venereology and Leprology. 2005;71(6):386–392.
  5. International Working Group on the Diabetic Foot (IWGDF). IWGDF Guidelines on the Prevention and Management of Diabetes-Related Foot Disease. 2023.
  6. American Diabetes Association Professional Practice Committee. Standards of Care in Diabetes — 2024 (Section 12). Diabetes Care. 2024;47(Suppl 1).
  7. Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 7th ed. Elsevier; 2021.
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