09 Jun Foot Blisters: Causes & Prevention
Are you about to run a long-distance race or do a trek for charity and are worried about getting foot blisters? Have painful blisters stopped you from engaging in favourite sports and activities? Do you have footwear that always results in blisters forming every time you wear them?
Foot blisters are one of the most common foot injuries we see at footinjuryclinic, whether they are in sportspersons or regular, everyday individuals. You can have blisters on your toes, bunions, heels, the ball of your foot as well as blood blisters. Let’s unpack why they occur and what can be done to heal them.
What is a blister?
Each foot is made up of 26 bones, 30 joints and more than 100 muscles, tendons and ligaments that all work together, with every layer of soft tissue between your bones and skin structurally connected. When you move, your foot bones move too, but the skin on your feet, your socks and shoes tend to be stationary. When the bones in your feet move but the skin does not, all the soft tissue in between stretches and distorts. This is called a shear distortion. Once this tear occurs, it slowly fills with fluid and is called a blister.
Why do blisters occur?
Most of us think that foot blisters result from some combination of heat, moisture and friction in our footwear. Heat results in sweat, sweat means moisture, and moisture results in more friction. When things rub more on the foot, blisters occur. However, we need to look at the word “friction” a bit closer. It means both rubbing together, and rubbing less when there is resistance to movement from one surface over another.
A blister will start off with its roof (top layer of skin) intact. The good thing is that it can’t get infected if it stays like this because when the roof is intact, the skin is keeping the blister fluid in and keeping germs out. As soon as you notice a blister forming, protect the blister roof by putting a plaster on it. Make sure to use an absorbent, non-stick pad on the blister roof – do not apply anything sticky directly onto the blister as it will get ripped off when you remove it – ouch!
Stages of a blister
If the blister roof tears, it becomes open to infection. In this case, you need to put some antiseptic on it to kill germs. If possible, keep the torn blister roof in place since the skin protects the raw blister base. Use an island dressing which has an absorbent pad with an adhesive backing to absorb excess wound fluid and provide a protective barrier. Make sure you change the dressing if you can see blister fluids or if it gets wet after a shower.
If a blister roof rubs off, it is called a “deroofed” blister, which is far more painful and takes longer to heal. The skin needs to be strong to grow back over the raw blister base so make sure you use a hydrocolloid blister plaster like a Compeed plaster. A blister could take a week or more to heal, so make sure you monitor it every time you change the dressing.
You know your blister is infected when you see pus (yellow blister fluid), feel increased pain, swelling, redness, warmth or you see red streaks extending from the blister. Seek medical help immediately.
As the saying goes, prevention is better than cure. The main aim of treating this blister is to prevent infection. Blister prevention is all about either increasing the skin’s resilience to shear distortion, reducing the severity of the blister and reducing the number of shear distortions. Here are some tips to prevent blisters:
- Wear shoes that fit correctly. Get our podiatrists to make sure you are wearing the right pair to suit your activity and the type of feet you have.
- Protect your feet by wearing clean, moisture-wicking socks.
- If you feel a blister forming, stop your activity to prevent the blister from getting worse.
- Wear blister patches like ENGO to reduce friction if you know you are playing high-impact sports or doing an endurance activity like running a marathon.