What is the appropriate treatment for a patient with a blood blister?

Treatment for Blood Blister

For a blood blister, pierce it at the base with a sterile needle to drain the fluid while leaving the blister roof intact to serve as a natural biological dressing, then apply a bland emollient and cover with a nonadherent sterile dressing. 1, 2

Initial Assessment and Decision Algorithm

The management approach depends on whether the blister is causing discomfort:

• Asymptomatic, small blood blisters without pressure pain: Leave completely intact and observe 3
• Pressure-painful or tense blood blisters: Proceed with drainage while preserving the roof 1, 2, 3
• Already ruptured blisters without infection: Leave remnants of the roof in place 3
• Ruptured blisters with signs of infection: Remove the blister roof completely 3

Step-by-Step Drainage Technique (When Indicated)

When drainage is necessary, follow this precise protocol:

1. Cleanse gently with antimicrobial solution, taking care not to rupture the blister 1, 2

2. Pierce at the base with a sterile needle, bevel facing up, selecting a site where gravity will facilitate drainage and discourage refilling 1, 2

3. Apply gentle pressure with sterile gauze swabs to facilitate drainage and absorb fluid 1, 2

4. Never deroof the blister - the roof acts as a protective biological dressing that reduces pain and infection risk 1, 2, 4, 5

5. Cleanse again with antimicrobial solution after drainage 1

6. Apply bland emollient such as 50% white soft paraffin and 50% liquid paraffin to support barrier function and encourage re-epithelialization 1, 2, 5

7. Cover with nonadherent dressing using aseptic technique 1, 2, 4

Pain Management

• Offer analgesia prior to the drainage procedure, as patients commonly report pain or burning sensation during blister care 1, 4
• Over-the-counter analgesics are appropriate for ongoing pain management 5

Infection Prevention and Monitoring

Daily surveillance is critical because infection represents a significant risk:

• Perform daily washing with antibacterial products to decrease colonization 1, 2
• Change dressings using aseptic technique 1, 2, 4
• Monitor for signs of infection: increasing erythema, purulent drainage, foul odor, or systemic signs 1, 5
• Obtain bacterial and viral swabs if clinical signs of infection appear 1, 2
• Apply topical antimicrobials only for short periods and only to areas with clinical infection - not prophylactically 1, 2, 4, 5
• Use systemic antibiotics only if local or systemic signs of infection are present 1, 5

Documentation

Document daily on a blister chart the number and location of new or changing blisters to track disease progression 1, 2, 4

Critical Pitfalls to Avoid

• Never deroof or remove the blister roof - this increases pain, infection risk, and delays healing 1, 2, 4, 5, 3
• Never apply topical antimicrobials prophylactically to intact blisters 1, 2, 4
• Never use antibiotics routinely - reserve for clinically infected lesions only 1, 5
• For large blisters requiring drainage, use a larger needle and pierce more than once if needed 1

Special Considerations

Oral blood blisters (angina bullosa haemorrhagica) are benign and require no treatment - they resolve spontaneously 6. These typically affect middle-aged and elderly patients and are often related to minor trauma 6.

The evidence strongly supports preserving the blister roof as it provides a sterile barrier, significantly decreases pain compared to deroofing, and demonstrates better healing outcomes 5, 7. Clinical experience from friction blister studies confirms that draining intact blisters while maintaining the roof results in the least patient discomfort and may reduce secondary infection risk 7.