What causes a nail plate to fall off?

Causes of Nail Plate Detachment

A nail plate can fall off due to various causes including fungal infections, trauma, systemic diseases, or inflammatory conditions that affect the nail matrix or bed, leading to separation and eventual detachment of the nail plate.

Common Causes of Nail Plate Detachment

Fungal Infections (Onychomycosis)

• Distal and Lateral Subungual Onychomycosis (DLSO)

  • Most common form (80% of cases)
  • Affects hyponychium at lateral edges initially
  • Spreads proximally along nail bed
  • Eventually the nail plate becomes friable and may break up due to trauma or keratolytic properties of dermatophytes 1
  • Primarily caused by Trichophyton rubrum 1

• Superficial White Onychomycosis (SWO)

  • Less common than DLSO
  • Affects surface of nail plate rather than nail bed
  • White discoloration with flaky nail surface 1
  • Usually caused by T. mentagrophytes 1

• Total Dystrophic Onychomycosis

  • Advanced stage where nail plate is almost completely destroyed 1
  • Can result from progression of any other form of onychomycosis

Trauma-Related Causes

• Direct trauma to the nail plate
• Repetitive microtrauma from:
  • Ill-fitting shoes
  • Sports activities (especially running)
  • Occupational hazards

Inflammatory Conditions

• Psoriasis

  • Can cause onycholysis (separation of nail from nail bed)
  • Eventually leads to complete nail detachment in severe cases 2

• Lichen planus

  • Affects nail matrix
  • Can cause permanent nail loss

Systemic Conditions

• Peripheral vascular disease

  • Compromises blood supply to nail unit
  • Can lead to nail dystrophy and detachment 1

• Raynaud's phenomenon

  • Associated with distal nail infections and eventual loss 1

Other Specific Causes

• Onychomadesis

  • Proximal separation of nail plate from nail matrix
  • Due to temporary cessation of nail growth
  • Often follows viral illnesses (especially hand-foot-mouth disease)
  • Complete nail shedding occurs 1-2 months after the triggering event 3

• Chronic paronychia

  • Inflammation of nail folds
  • Often occurs in people with wet occupations
  • Can lead to proximal nail dystrophy and eventual detachment 1

• Brittle nail syndrome

  • Affects up to 20% of population, especially women over 50
  • Characterized by nails that split, flake, and crumble
  • Can lead to progressive nail fragility and eventual loss 4

Pathophysiological Process

The nail plate detachment typically follows this progression:

1. Initial damage to nail matrix, nail bed, or surrounding tissues
2. Onycholysis (separation of nail plate from nail bed) 2
3. Progressive weakening of attachment between nail plate and bed
4. Complete detachment of the nail plate

In fungal infections specifically:

• Fungi invade the nail bed and/or plate
• Keratolytic enzymes from dermatophytes break down nail keratin
• Subungual hyperkeratosis develops
• Nail becomes friable and eventually detaches 1

Clinical Pearls and Pitfalls

• Diagnostic pitfall: Assuming all nail detachment is fungal in origin. Remember that approximately 50% of nail dystrophies are non-fungal 5

• Treatment pitfall: Initiating antifungal treatment without laboratory confirmation. Always confirm diagnosis through mycological testing before starting treatment 5

• Clinical pearl: When a nail falls off, examine for signs of surrounding skin infection (tinea pedis) which often accompanies fungal nail infections 1

• Clinical pearl: Nail regrowth after complete detachment typically takes 6-12 months for toenails and about 6 months for fingernails 1

• Prevention pearl: For those prone to nail detachment, avoid prolonged water exposure, ensure proper shoe fit, and maintain good nail hygiene 5