BASICS
- Description: Nail plate margin penetrates lateral nail fold → irritation, inflammation, possible bacterial/fungal infection.
- Stages:
- Stage 1: Inflammation – erythema, edema, tenderness.
- Stage 2: Abscess – increased pain, purulent/serous drainage.
- Stage 3: Granulation – chronic inflammation with granulation tissue and nail fold hypertrophy.
- Synonyms: Onychocryptosis, unguis incarnatus.
EPIDEMIOLOGY
- Great toenail most commonly affected.
- Lateral edge > medial edge.
- Most common in males aged 14-25 years.
- More frequent in elderly females than elderly males.
- Prevalence: ~2.5% general population; 5% in >65 years; male:female ratio 2:1.
ETIOLOGY AND PATHOPHYSIOLOGY
- Nail plate invades nail fold → foreign body inflammatory reaction.
- Secondary bacterial/fungal infection possible → abscess.
- Chronic inflammation → granulation tissue and hypertrophy of nail fold.
RISK FACTORS
- Genetic predisposition.
- Increased nail fold width, decreased nail thickness.
- Medial rotation of toe.
- Thickened/distorted nails, fungal infections.
- Improper nail trimming.
- Poorly fitting shoes.
- Trauma to nail or fold.
- Conditions causing pedal edema (thyroid disease, diabetes, obesity, heart/renal failure).
PREVENTION
- Properly fitting footwear.
- Correct nail trimming (straight across, not too short, avoid rounding corners).
DIAGNOSIS
History
- Pain, redness, swelling along one or both sides of nail.
- Possible drainage (serous or purulent).
Physical Exam
- Tenderness, erythema, edema of nail fold.
- Drainage if abscess present.
- Granulation tissue and lateral nail fold hypertrophy in chronic stages.
Differential Diagnosis
- Cellulitis
- Felon (pulp abscess)
- Onychogryphosis
- Onycholysis
- Onychomycosis
- Osteomyelitis
- Paronychia
- Subungual exostosis or osteochondroma
Diagnostic Tests
- Usually none.
- X-ray, MRI, or bone scan if osteomyelitis suspected.
- X-ray if bony tumors suspected.
TREATMENT
General Measures
- Mild (stage 1) often responds to conservative care:
- Warm soapy water or Epsom salt soaks (10-20 min, 3x daily).
- Gently lift ingrown nail edge with cotton or dental floss.
- Use tape to pull lateral nail fold away from nail plate.
Medications
- NSAIDs for pain.
- Topical antibiotics after soaking.
- Oral/topical antibiotics not useful adjuncts to surgery.
Surgery
- Partial nail avulsion with phenol matrix ablation is most common and effective surgical treatment.
- Procedure:
- Digital block anesthesia.
- Tourniquet for hemostasis (caution in diabetes/PVD).
- Longitudinal nail incision and removal of ingrown portion.
- Phenol application (80-88%) to nail matrix, neutralized by alcohol.
- Alternative matrix ablation: sodium hydroxide, cryotherapy, electrocautery, CO2 laser.
- Flexible gutter splint for stages 2-3 as nonsurgical option.
- Bilateral partial matricectomy for severe or recurrent cases.
ONGOING CARE
- Post-op dressing with antibiotic ointment or petroleum jelly.
- Elevate foot 12-24 hours post-op.
- NSAIDs for discomfort.
- Daily dressing changes and cleaning for 1-2 weeks.
- Nail regrowth may take 6-12 months without matrix ablation.
- Follow-up every 7-10 days until improvement.
PATIENT EDUCATION
- Trim nails straight, not rounded or too short.
- Wear comfortable, well-fitting shoes.
COMPLICATIONS
- Post-surgical cellulitis (uncommon).
- Nail bed or matrix damage → nail deformity.
- Distal toe ischemia (rare, prolonged tourniquet).
- Osteomyelitis (rare).
- Persistent drainage.
- Recurrence: 40-80% with avulsion alone; 0.6-14% with matrix ablation; 6-13% with gutter splint.
REFERENCES
- Mayeaux EJ Jr, Carter C, Murphy TE. Ingrown toenail management. Am Fam Physician. 2019;100(3):158-164.
- Thakur V, Vinay K, Haneke E. Onychocryptosis—decrypting the controversies. Int J Dermatol. 2020;59(6):656-669.
- Eekhof JAH, Van Wijk B, Knuistingh Neven A, et al. Interventions for ingrowing toenails. Cochrane Database Syst Rev. 2012;(4):CD001541.
- Park DH, Singh D. The management of ingrowing toenails. BMJ. 2012;344:e2089.
- Nazari S. A simple and practical method in treatment of ingrown nails: splinting by flexible tube. J Eur Acad Dermatol Venereol. 2006;20(10):1302-1306.
CLINICAL PEARLS
- Nonsurgical care effective in stage 1 and mild stage 2 ingrown toenails.
- Partial nail avulsion with phenol matrix ablation is the most common surgical intervention.
- Proper nail trimming and shoe fitting prevent recurrence.
- Antibiotics are not indicated adjuncts to surgery.