Treatment of Bleb (Blister) on a Child's Finger
For a simple fluid-filled blister on a child's finger, leave the blister intact and apply white soft paraffin ointment every 2 hours to promote healing, or if the blister is large and interfering with function, pierce it with a sterile needle to drain the fluid while preserving the blister roof as a natural biological dressing. 1
Initial Assessment
Before treating, quickly evaluate for:
- Signs of infection including crusting, weeping, purulent discharge, increasing redness, warmth, or fever—these indicate bacterial infection (commonly Staphylococcus aureus) requiring different management 2, 3
- Grouped vesicles or punched-out erosions suggesting herpes simplex virus (herpetic whitlow), which requires antiviral therapy rather than drainage 2, 4
- Mechanism of injury to determine if this is a simple friction blister versus a burn, bite wound, or puncture injury 3, 4
Primary Treatment for Simple Blisters
If the Blister is Small and Not Interfering with Function:
- Leave the blister completely intact as the blister roof acts as the best biological dressing to prevent secondary bacterial infection 1
- Apply white soft paraffin ointment every 2 hours to the intact blister to prevent drying, support barrier function, and reduce transepidermal water loss 2, 1
- Avoid adhesive dressings as they cause additional trauma upon removal 2
- Use tubular or gauze bandages to secure any protective covering rather than adhesive tape 1
If the Blister is Large or Functionally Limiting:
- Pierce the blister at its base with a sterile needle to release fluid while preserving the blister roof 1
- Select a drainage site that allows gravity-assisted drainage 1
- Gently apply pressure with sterile gauze to facilitate drainage and absorb fluid 1
- Never remove the blister roof (de-roof) during drainage—the dead skin layer provides optimal protection 1
- Cleanse gently with an antimicrobial solution before drainage 1
- After drainage, apply white soft paraffin ointment (or a 50% white soft paraffin/50% liquid paraffin mixture) to encourage re-epithelialization 1
- Cover with a non-adherent dressing secured with tubular or gauze bandages 1
Infection Prevention
- Change dressings using aseptic technique to minimize contamination risk 1
- Daily washing with an antibacterial product can decrease bacterial colonization 1
- Avoid soaps and detergents as they remove natural lipids and worsen barrier function 2
When to Escalate Treatment
Signs Requiring Urgent Reassessment:
- Increasing pain, redness, or swelling beyond 24-48 hours 2
- Purulent discharge or fever indicating systemic infection 2
- Grouped vesicles appearing suggesting herpes simplex requiring antiviral therapy 2
- Difficulty using the hand due to worsening pain 2
If Infection Develops:
- Consider topical antimicrobials for short periods if signs of infection appear 1
- For established bacterial infection, oral flucloxacillin remains the treatment of choice for staphylococcal skin infections in children 3
- Cefalexin or erythromycin are suitable alternatives with broader coverage 3
- Treatment duration of 7 days is as effective as 10 days for uncomplicated skin infections 3
Critical Pitfalls to Avoid
- Never use topical anesthetics in young children due to accidental ingestion risk 2
- Do not apply occlusive ointments if infection is present as they may increase infection risk 5
- Avoid aggressive manipulation that could introduce bacteria or cause additional trauma 1
- Do not confuse herpetic whitlow with bacterial infection—herpetic whitlow typically resolves without intervention and does not require drainage 4
Follow-Up Care
- Monitor for signs of healing versus infection over the next 48-72 hours 1
- Document the blister location and size to track progress 1
- Ensure parents understand proper home care including when to seek further medical attention 1
- Most simple friction blisters heal within 5-7 days with conservative management 1