Blisters are considered partial thickness wounds — along with abrasions, shallow cuts, and second degree burns — and are at low risk for bacterial infection. Damage is confined to the epidermis or epidermis/upper dermis. Essentially the skin remains intact and there is minimal danger of microorganisms entering the subcutaneous tissue. Bleeding indicates damage to the dermis; the greater the bleeding the greater the damage. And, the more the dermis is damaged, the greater the inflammatory response. Capillaries in the dermis, together with fibroblasts, secrete collagen. New skin cells are constructed from the collagen and migrate over the dermis, building from the inside out. Collagen forms faster in a moist– versus dry–environment.
Friction and pressure combine to create shear forces that stretch and irritate connective tissue within the epidermis initially creating a “hot spot”. Later—as the epidermis tears and plasma leaks into the torn tissue—a blister forms. As long as shear forces are present the skin continues to delaminate and the blister grows until it breaks. More pressure — due to a heavy pack or persistent hiking downhill — will cause deeper damage and a more painful blister. Both the prevention and treatment of friction blisters focus on reducing shear forces within the skin; in many cases this requires adding an external “sliding layer.”
- Dirty skin increases surface friction. Wash skin, socks, etc. on a regular basis. Wear gaiters over boot tops and laces to keep dust and dirt out.
- Wet, saturated skin weakens the epidermis making it more susceptible to shear forces. Keep skin, socks, gloves etc. dry. Change socks regularly. Sleep in clean dry socks. For some people a antiperspirant helps keep feet dry.
- A rapid increase in shear forces over normal use doesn’t allow enough time for connective tissue to adapt. Increase load/pack weight and distance slowly to allow the skin to adapt to new forces. Avoid continuous downhill hiking until skin has had time to strengthen.
- Poor-fitting footwear creates pressure spots. Make sure footwear, gloves and clothing fit well.
- No external sliding layer predisposes skin to blisters. Anticipate blisters; treat hot spots immediately BEFORE they become a blister by adding an external sliding layer to reduce shear forces within the skin. You can to low tech or high tech; if the low tech method doesn't work for you, the high tech will. Low tech: paint the "hot" area with tincture of Benzoin and cover with tape — cloth tape, flexible medical tape, or duct tape. High tech: add a friction patch (ENGO®) to footwear to create a sliding layer between the outer sock and footwear.
NOTE: Whether you go low or high tech, our web store carries everything you need to prevent and treat blisters.
If you are at home, wear flip-flops until the blister reabsorbs and heals; this will take a week or two. If you want to keep hiking then:
- Remove skin lid over blister to prevent it from enlarging due to continued pressure from footwear.
- Cover the exposed blister with a hydrogel dressing (preferred) or petroleum jelly and gauze to promote healing and decrease pain.
- Secure in place with porous cloth tape or flexible medical tape (preferred). Use Tincture of Benzoin prior to taping so tape adheres to skin.
- Add a ENGO® blister patch to footwear or socks to reduce friction and its accompanying shear forces.