What is the treatment for a blood blister?

Treatment of Blood Blisters

For blood blisters, the optimal treatment is to drain the blister by piercing it at the base with a sterile needle while keeping the blister roof intact as a biological dressing, then apply a non-adherent occlusive dressing to promote wound healing. 1

Initial Management

1. Draining the blister:

   • Use a sterile needle to pierce the blister at its base
   • Keep the blister roof intact as it serves as a natural protective dressing 2, 1
   • Leave small to medium blisters intact if they're not causing discomfort 2
   • Only drain larger blisters that are painful or interfere with function (such as on the sole of the foot) 2

2. After draining:

   • Apply a bland emollient such as 50% white soft paraffin/50% liquid paraffin to support barrier function 1
   • Cover with a non-adherent dressing (like Mepitel™ or Telfa™) 1
   • Apply a secondary foam dressing to collect any exudate 1

When to Remove the Blister Roof

• Only remove the blister roof if:
  • There are clinical signs of infection
  • The blister is already ruptured 1
  • Otherwise, evidence shows that keeping the blister roof intact improves healing and reduces pain 2

Infection Prevention

• Monitor for signs of infection:

  • Increasing redness, warmth, pain
  • Presence of pus
  • Red streaks extending from the blister 1

• If infection develops:

  • Seek medical attention
  • Oral antibiotics may be necessary (options include Dicloxacillin, Cephalexin, Clindamycin, or Amoxicillin/clavulanate) 1

Additional Care Measures

• For painful blisters:

  • Consider over-the-counter pain relievers like acetaminophen or NSAIDs 1
  • Avoid home remedies that might introduce infection

• For extensive areas of erosion:

  • Consider antiseptic baths or soaks with potassium permanganate 2
  • Antiseptic-containing bath oils may be used for a few days to dry lesions and prevent infection 2

Prevention of Future Blood Blisters

• Choose properly fitted footwear with a rounded toe box and flexible sole 1
• Wear moisture-wicking socks 1
• Use cornflour on areas prone to blisters to control moisture and reduce friction 1
• Protect "hot spots" with protective padding or tape 1
• Recent exposure to repeated low-intensity friction forces can lead to epidermal thickening, which may reduce blister likelihood 3

Special Considerations

• Ensure tetanus immunization is up-to-date for traumatic blisters 1
• Seek urgent medical attention if:
  • The blister is large (>30% body surface area)
  • It involves mucous membranes
  • There are signs of systemic illness 1

Common Pitfalls to Avoid

• Do not apply ice or ice water to blisters as this can increase tissue damage 2
• Avoid rupturing the blister in a non-sterile manner, which increases infection risk
• Don't remove the blister roof unnecessarily as it serves as a natural protective barrier 2
• Avoid using adhesive bandages directly on the blister as they can cause further damage when removed

By following these evidence-based guidelines, most blood blisters will heal without complications within a few days to a week, with proper protection and care being the cornerstones of management.