Ingrown toenail

Infection beneath the lateral nail fold or cuticle

Epidemiology

• Estimated 2.5-5% prevalence

Risk factors (for distal-lateral ingrowing)

• Improper nail plate trimming to round the edges
• Poorly-fitting shoes
• Hyperhidrosis
• Repeated minor trauma
• Congenital or acquired foot deformities
• Drug-induced paronychia

Pathophysiology

• Distal-lateral ingrowing
  • A sharp spicule of the distal-lateral nail plate edge penetrates and injures the soft tissues of the lateral nail fold, causing a foreign body, granulomatous reaction
• Distal ingrowing
  • Following nail plate avulsion, the hyponychium becomes hypertrophic and the nail plate embeds into the distal pulp
• Retronychia
  • Incomplete nail shedding, leading to embedding of the nail into the proximal nail fold and subsequent inflammation

Presentation

• Stage 1 - Initial embedding of the nail spicule into the nail fold. Slight erythema and swelling. Pain when touching the area or wearing tight shoes.
• Stage 2 - Severe inflammation with seropurulent discharge. Pain can be severe.
• Stage 3 - Formation of granulation tissue, that will undergo epithelialization with hypertrophy of the lateral nail fold.

Differential diagnosis

• Acute paronychia
• Herpetic whitlow
• SCC

Initial management

• Cut nail straight, without rounding the corners
• Wear open toe or box toe shoes

Non-operative

• Cotton nail cast
  • Remove the nail spicule
  • Lift and separate the nail edge from soft tissue
  • Place a piece of gauze or dental floss underneath, to stop the nail growing into the nail fold
  • Will need to be replaced weekly until outgrowth
• Gutter treatment
  • Cut a piece of IV tubing open to form a gutter, then slide it under the nail to prevent ingrowth (6-8 weeks)

Indications for surgery

• Severe
• Extremely painful
• Recurrence

Surgical goals:

• Permanent reduction in width of the nail plate, or a reduction of the periungual soft tissues

Wedge resection:

• Aim to excise about a quarter of the nail, the nail fold, the nail wall and nailbed
• Ring block
• Glove tourniquet
• Mobilise and excise about a quarter of the nail on the affected side (3-5mm), using Gillies and Metz scissors. Avoid lifting the nail too much in the middle, as that needs to stay intact and attached.
• Lift the nail fold by making an oblique cut at the base of the nail. Options to destroy germinal matrix:
  • Excise with scalpel
    • The stuff you need to get rid of is the whitish tissue - basically cut down to bone
  • Apply 88% phenol (be very careful not to get any on skin) - Cochrane review demonstrated much lower recurrence rate. Apply paraffin to skin to protect it. Clean skin and apply alcohol to skin afterwards.
  • Diathermy
  • Curette
• Close the cut with a single Prolene suture
• Jelonet on top of nail, gauze, crepe
• Review in clinic 2/52
  • Dressing off
  • Clean
  • Suture out
• Patient can then commence betadine soaks daily and go back to wearing loose shoes

Zadek's procedure

• Indications:
  • Recurrent disease after adequately-performed wedge resection
  • Patient preference - prior to long periods of inaccessible medical care
• Technique
  • As per wedge resection, except remove entire nail
  • Ablate entire matrix with phenol