Friction blisters are one of the simplest yet most frequently encountered minor injuries at the pharmacy counter. They result from repeated mechanical friction against the skin — typically from ill-fitting footwear, new shoes, or prolonged walking and running. While most heal without complication, incorrect management can lead to secondary infection, and certain blister presentations require referral rather than self-care.
How Friction Blisters Form
When skin is subjected to repeated shearing forces, the outer layer (epidermis) separates from the deeper layers. The resulting pocket fills with clear serous fluid, which acts as a natural protective cushion over the damaged tissue beneath. This fluid is sterile and contains growth factors that promote healing.
The most common sites are the heels, toes, ball of the foot and the back of the ankle — all areas where footwear creates friction. Blisters on the hands (from tools, gym equipment or rowing) are also frequently seen.
To Pop or Not to Pop?
This is the question pharmacists hear most often. The evidence-based answer:
Leave intact blisters alone whenever possible. The unbroken skin over a blister is the best natural dressing — it is sterile, breathable and promotes optimal healing underneath. Most friction blisters heal within 5–7 days if left undisturbed.
Exceptions where draining may be appropriate:
- The blister is large (>2 cm), tense and painful, making walking or daily activities difficult
- The blister is in a weight-bearing location that will inevitably rupture from continued friction
If draining is needed:
- Clean the area with antiseptic (chlorhexidine or povidone-iodine)
- Use a sterile needle (available in pharmacy first aid kits) to puncture the edge of the blister at two points
- Gently press the fluid out
- Leave the roof of the blister in place — do not peel it off
- Apply an antiseptic and cover with a hydrocolloid blister plaster or non-adherent dressing
Never drain:
- Blood blisters (the blood is from deeper tissue damage and draining increases infection risk)
- Blisters in diabetic patients (see referral section below)
- Burn blisters (different mechanism, different management)
Pharmacy Treatment
For intact blisters
- Hydrocolloid blister plasters (Compeed, Scholl Blister Shield) — these are the gold standard pharmacy product. They provide cushioning, absorb moisture, reduce friction and create an optimal moist healing environment. They can be left in place for several days until they start to peel
- Moleskin or adhesive felt padding — can be cut to create a donut-shaped pad around the blister, relieving pressure from the centre
- Soft silicone gel toe protectors — for toe blisters from narrow footwear
For open/deroofed blisters
- Clean with antiseptic — chlorhexidine-based wound wash or saline
- Apply a non-adherent dressing (Melolin, Mepitel) to prevent the dressing sticking to the raw wound bed
- Hydrocolloid plasters also work well on open blisters — they absorb exudate and protect against further friction
- Antiseptic cream (Savlon, germolene) — a thin layer can be applied before dressing
- Do not use plain adhesive plasters directly on open blisters — they stick to the wound bed and cause pain on removal
Pain relief
- Paracetamol or ibuprofen — for painful blisters affecting mobility
- Most friction blisters are more uncomfortable than truly painful, and a well-applied hydrocolloid plaster provides immediate pressure relief
Signs of Infection: When to Refer
Advise patients to see their GP or practice nurse if a blister shows signs of secondary infection:
- Increasing redness spreading beyond the blister margin
- Warmth and swelling around the site
- Pus or cloudy fluid (clear serous fluid is normal)
- Red streaks tracking from the blister toward the groin or armpit (lymphangitis — urgent referral)
- Fever or feeling systemically unwell
- Pain that is worsening rather than improving after 48 hours
Diabetic patients
Patients with diabetes should be referred to their GP or podiatrist for any foot blister rather than self-managing. Diabetic neuropathy can mask pain, leading to continued friction and tissue breakdown, and diabetic peripheral vascular disease impairs healing. A simple friction blister in a diabetic patient can progress to a serious foot ulcer if not managed appropriately.
Prevention Advice
Prevention is always more effective than treatment. Pharmacists can recommend:
| Measure | Detail |
|---|---|
| Break in new shoes gradually | Wear for 1–2 hours initially, increasing daily |
| Wear moisture-wicking socks | Merino wool or synthetic wicking fabrics reduce friction more than cotton |
| Use blister prevention products | Compeed Anti-Blister Stick, Body Glide, or petroleum jelly on friction-prone areas |
| Ensure correct shoe fit | Shoes should have thumb-width space at the toe; heels should not slip |
| Keep feet dry | Change socks during long walks; use foot powder if feet sweat excessively |
| Double-layer socks | Specialist hiking socks with a liner layer reduce shearing forces on the skin |
| Address biomechanical issues | Patients with recurring blisters in the same location may benefit from podiatry referral for orthotic assessment |
Seasonal Relevance
Blister queries peak in pharmacy during three periods:
- Spring/summer — new sandals, summer shoes and increased walking
- Pre-holiday — customers buying new footwear for travel
- September — return to school with new shoes; back-to-work after summer breaks
Stocking hydrocolloid blister plasters prominently during these periods is both a patient service and a commercial opportunity.
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Sources: NHS England, NICE CKS Wound Management, St John Ambulance, British Journal of Sports Medicine (blister prevention in athletes).