How to treat a foot blister?

Treatment of Foot Blisters

For simple friction blisters on the foot, leave intact blisters undisturbed when possible, but drain large or functionally limiting blisters with a sterile needle while preserving the blister roof, then protect with low-adhesion dressings. 1

Immediate Management Based on Blister Characteristics

Intact Small Blisters

• Leave the blister intact as the roof provides natural protection against secondary bacterial infection 1
• The blister fluid is similar to plasma composition and the intact roof serves as an optimal biological dressing 2

Large or Functionally Limiting Blisters

• Pierce with a sterile needle at the lowest point to facilitate gravity drainage while maintaining the blister roof in place 1
• This approach is particularly important for blisters on weight-bearing areas like the sole of the foot where they interfere with function 1
• Clinical experience suggests this method results in the least patient discomfort and may reduce secondary infection risk 2

Deroofed or Ruptured Blisters

• Apply hydrocolloid dressings for pain relief and to allow continuation of physical activity if necessary 2
• Cover painful eroded areas with low-adhesion dressings such as Mepitel® or Atrauman® held in place with soft elasticated viscose 1
• For extensive erosions, consider antiseptic baths (potassium permanganate) or antiseptic-containing bath oils for a few days to dry lesions and prevent infection 1

Key Management Principles

What NOT to Do

• Do not use antibiotics routinely - there is no evidence that antibiotics influence blister healing 2
• Avoid aggressive debridement of the blister roof unless already completely deroofed 1

Wound Healing Timeline

• New cell proliferation begins at the blister base within 6 hours of formation 2
• High mitotic activity occurs in basal cells at 24 hours 2
• New stratum granulosum forms at 48 hours and stratum corneum at 120 hours 2

Prevention for Future Episodes

Footwear Modifications

• Ensure properly fitting shoes that are broken in gradually 3
• Consider closed-cell neoprene insoles, which have evidence for reducing blister incidence 2
• Use acrylic socks or a combination of thin polyester sock with thick wool/polypropylene sock that maintains bulk when exposed to sweat 2

Skin Preparation

• Apply drying foot powders, which demonstrate a barrier effect and significantly reduce near-surface skin hydration (reduction of 8.53 AU) 4
• Use protective padding over potential blister sites 3
• Note that antiperspirants with emollients do not appear to decrease blister probability 2

Common Pitfalls to Avoid

• Do not completely remove the blister roof unless it is already fully deroofed - the roof provides optimal protection 1, 2
• Avoid wide-area fixation dressings as they demonstrate higher drop-out rates (11.7% vs 4.0%), delayed healing (51.9% vs 35.3%), and lower satisfaction compared to simple adhesive tape 5
• Do not assume moist skin is protective - increased skin surface hydration is actually a risk factor for blister formation 4