How to treat a blister containing a collagenated substance?

Management of Blisters Containing Collagenated Substance

For blisters containing collagenated substance, drain the blister by piercing it at its 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, 2

Assessment and Initial Management

1. Evaluate the blister:

   • Size, location, and whether it is intact or ruptured
   • Presence of pain, redness, or signs of infection
   • Whether it is causing functional impairment

2. Blister drainage procedure:

   • Gently cleanse the blister with antimicrobial solution 2
   • Pierce the blister at its base with a sterile needle (bevel facing up) 1, 2
   • Select a site where fluid will drain by gravity to prevent refilling 2
   • Apply gentle pressure with sterile gauze to facilitate drainage 2
   • Do not remove the blister roof (keep as a biological dressing) 1, 2, 3
   • After drainage, gently cleanse again with antimicrobial solution 2

Dressing Application

1. Apply appropriate dressing:

   • Cover with an occlusive dressing to promote wound healing 1
   • Consider a non-adherent dressing like Mepitel™ or Telfa™ 2
   • Apply a bland emollient such as 50% white soft paraffin/50% liquid paraffin to support barrier function and encourage re-epithelialization 1, 2

2. Dressing changes:

   • Change dressings using aseptic technique 1, 2
   • Monitor for signs of infection during dressing changes
   • Provide appropriate analgesia before dressing changes as many patients report pain during wound care 2

Special Considerations

1. When to remove the blister roof:

   • If there are clinical signs of infection 4
   • If the blister is already ruptured with signs of infection 4
   • For burns of grade 2a or higher 4

2. Pain management:

   • Offer analgesia prior to blister care procedures 2
   • Consider acetaminophen or NSAIDs if needed 2

3. Monitoring for complications:

   • Watch for signs of infection (increasing redness, warmth, pain, pus, or red streaks) 2
   • If infection develops, consider topical antimicrobials for short periods 1
   • Use systemic antibiotics if there are local or systemic signs of infection 1

Scientific Background

The fluid in blisters contains various components including collagen propeptides, which are cleaved during collagen synthesis 5. Research has shown that blister fluid contains high concentrations of collagenase inhibitor, which may play a role in limiting blister formation and assisting in wound repair 6. This collagenated substance is part of the natural healing process.

Blisters form when frictional forces mechanically separate epidermal cells at the level of the stratum spinosum, and the area fills with fluid similar to plasma but with lower protein content 7. After blister formation, cells in the blister base begin taking up amino acids and nucleosides within 6 hours, with high mitotic activity in basal cells at 24 hours 7.

Follow-up Care

• Inspect the wound daily for signs of healing or infection
• Continue dressing changes until re-epithelialization occurs
• Seek medical attention if signs of infection develop or if healing is delayed
• Document the number and location of blisters to track progress 2

The evidence strongly supports maintaining the blister roof as a biological dressing while draining the fluid, as this approach provides the best outcomes in terms of patient comfort and reduced risk of infection 1, 2, 3, 7.