What is the treatment for bullae with blood in the metatarsal arch?

Treatment of Blood-Filled Bullae in the Metatarsal Arch

For blood-filled bullae in the metatarsal arch, the primary treatment is to drain the blister while leaving the roof intact, followed by appropriate offloading of the affected area using a non-removable knee-high device if possible.

Initial Management

Blister Management

• Drain but preserve the blister roof:
  • Pierce large blisters with a sterile needle to release fluid while keeping the blister roof intact as it forms a natural protective dressing 1
  • Leave small to medium blisters intact if they're not causing significant discomfort 1
  • Only remove loose, fluttering skin after the blister has broken naturally 1

Wound Care

• Clean the area with antiseptic solution if there are signs of infection
• For painful areas, consider covering with low-adhesion dressings such as Mepitel or Atrauman 1
• If extensive erosions are present, antiseptic baths (e.g., potassium permanganate) or antiseptic-containing bath oils may help dry lesions and prevent infection 1

Offloading Interventions

Primary Offloading Options

1. First-line treatment: Non-removable knee-high offloading device

   • Total contact cast (TCC) or non-removable knee-high walker 1
   • Choose based on patient factors and local resources
   • Most effective for promoting healing and preventing recurrence

2. Second-line treatment (if non-removable device is contraindicated or not tolerated):

   • Removable knee-high or ankle-high offloading device 1
   • Encourage consistent use during all weight-bearing activities

3. Third-line treatment (if offloading devices unavailable):

   • Felted foam in combination with appropriate footwear 1

Important Considerations

• Do not use conventional or standard therapeutic footwear alone as primary treatment 1
• Consider a shoe lift on the contralateral limb to improve comfort and balance 1
• For diabetic patients with infection, adjust offloading approach based on infection severity:
  • Mild infection: Consider non-removable knee-high device 1
  • Moderate infection: Use removable offloading device 1
  • Severe infection: Address infection first, then use removable offloading 1

Surgical Interventions (for Persistent Cases)

If non-surgical offloading fails to heal the ulcer, consider surgical options:

• For metatarsal head ulcers:

  • Achilles tendon lengthening with offloading device 1
  • Metatarsal head resection with offloading device 1
  • Metatarsal osteotomy for ulcers on metatarsal heads 2-5 1

• For hallux ulcers:

  • Joint arthroplasty combined with offloading device 1, 2
  • Particularly effective for hallux ulcers with limited range of motion 2

Monitoring and Follow-up

• Regular assessment of wound healing progress
• Document wound size, surrounding cellulitis, and quality/quantity of drainage 1
• Use a sterile, blunt metal probe to measure wound depth and check for foreign bodies or bone involvement 1
• Adjust treatment based on healing progress

Special Considerations

• For diabetic patients: Assess vascular supply before any intervention 1

  • Check dorsalis pedis and posterior tibial pulses
  • Consider additional vascular testing if pulses are diminished

• For hyperkeratosis (common in metatarsal area):

  • Conservative debridement by a podiatrist 1
  • Avoid excessive debridement which can increase risk of blistering 1
  • Apply emollients and non-adherent dressings after debridement 1

• For signs of infection: Obtain appropriate cultures before starting antibiotics and treat according to culture results 1

Remember that proper offloading is the cornerstone of treatment for blood-filled bullae in the metatarsal arch, with the goal of preventing recurrence and promoting healing while minimizing the risk of infection and further tissue damage.