All About Blisters

Do you suffer with blisters on your feet or ankles?

They are a real problem for most people and yet, so often disregarded

Blisters are such a common problem that we see in clinic, and most are so painful and yet easily prevented, so we decided to create a whole website dedicated to the humble blister!

What are Blisters?

A blister occurs when a tear happens between the third and the fourth layer of the epidermis (outer layer of the skin). The tear opens and fills with fluid from the capillaries below and hence the blister is formed, blister development time can be up to 2 hours but also can be much quicker than that.

The tear in the skin is due to repeated SHEAR stresses caused by friction, bone movement, moisture, and pressure, directly applied to the skin.

Moisture

is when the skin gets wet either by being in water or sweating, this then increases the co-efficient of friction, in English, a bit like when you spit on your hands to get a better grip, this increases friction. So, we know that when feet get wet there is an increased grip with the shoes and socks which increases the friction between the skin and sock…causing blisters

Heat

doesn’t directly cause blisters but when feet get warmer in the hot weather, they naturally sweat, which means there is an increased amount of moisture on the skin, increasing friction and blisters.

Bone movement

every step you make the bones in the feet will move; this is perfectly normal. The problem is when the outer layer of the skin remains stationary and is stuck to the sock or shoe. The soft tissues in between the bones and skin, stretch and distort, then blisters are formed by the shear applied to that area of skin.

Pressure

what that means in practice means is force applied to the foot, either a down ward force caused by the body, for eg; carrying a 30kg back pack will increase the pressure down into and through the foot. Or an upward force from the ground (GRF) so for eg- different types of surfaces that you walk on. Concreate floor will exert a greater force (pressure) up the body than sand or grass. This applies to footwear, if shoes are too tight or poorly fitted then they will exert pressure on the foot causing blisters.

Skin resilience

skin is usually a very resilient organ but when it is exposed to repeated stressors that it is not used to, it eventually breaks down and the healing process cannot keep up with the repeated trauma and the result is blisters on your blisters! This resilience of the skin can be improved over time

So a blister formation is not due to just one cause but many, which is why a podiatrist can work out which one of these causes is creating your blisters and then help you to treat and prevent them.

Some people are blister prone, ie their shear strength of their skin is less than others and no matter what they do. They will struggle with blisters. However for others, preparation is key, they have worn the right fitting footwear, correct socks and taken the precautionary measures to remain blister free.

Blisters can take up to 6 weeks to heal, which creates massive problems for people participating in sporting activities that last for several days at a time. Blisters can be formed on the first day and then the completion of an event is unlikely. The fear of getting Blisters can for some prevent them carrying on their favourite sport or leisure activity and for those who like fashion shoes, a night out in your favourite shoes can be painful experience for the following 2 weeks in your work or casual shoes. They are very painful!!

Blisters are the most common reported injuries in runners, hikers and endurance athletes and we suspect in most ground contact activities as well

Blisters affect 54% of backpackers to 64% of long distance hikers, incidence in marathons are up to 39% affected. Ultramarathon multistage runners suffer 76% to 100%.

Military personnel struggle with 48%-65% blister formation after short marches and 33% after 12 month deployment. 84% of Cellulitis (Bacterial infection in the skin which spreads rapidly) in Military recruits is caused by blisters, this causes an average loss of 8 training days per recruit!

These statistics are huge, if these results had been recorded as any other injuries, something would have been done about it but most people tend to regard blisters as an acceptable part of an active lifestyle and they just don’t have to be.

Blister Treatment

Blisters have different stages and are treated in a different ways dependant on what stage the blister is in?

Hotspot

is when the skin starts to feel a little warmer than the surrounding skin and it may start to sting a bit, this is the warning stage and time to address it to prevent a fully formed blister.

Bubble Blister

the hotspot has progressed, the tear in the skin has been formed and a fluid filled bubble on the skin that most will recognise as a blister is now visible.

Roof torn blister

this has progressed from the intact blister and the roof or the top of the blister has a tear and the fluid has leaked out, so it is no longer looks like a bubble on the skin.

Roof off blister

the tear has now is so big that it has completely removed the roof of the blister and it is now, essentially an open wound and need to be treated as such.

Infected blister

is where the roof has come off the blister and the open wound has become infected by a bacterial infection, this wound needs to be immediately treated medically, as bacterial infections can easily spread up the leg and in to the blood system quickly, prompt medical attention is paramount.

It is very important to treat each Blister stage with the right products, otherwise it could make the blister worse. Recognising when a blister is infected is so important in saving your foot let alone finishing your race or walk.

Prevention is really the best form of treatment, if you know you get blisters or suspect you might, then wearing the correct footwear, taping, socks, using the right products is the key to success and completion of any planned event. There are so many products on the market, making it very difficult to choose the right one, a lot promise a great deal but if it is the wrong product for you or addressing the wrong stage of a blister then it will fail to succeed.

As podiatrists, we deal with feet problems all the time, we are the most experienced medical professionals in dealing with foot related issues.

You may see Podiatrists as part of a team in departments of Dermatology, Diabetes, Paediatrics, Musculoskeletal (Biomechanics) Sports injuries, Peripheral arterial disease (PAD), Rheumatology and Rehabilitation, Forensics, Podiatric Surgery as well as Podiatrists dealing with general routine podiatry in Hospitals, GP surgeries and private practice. As a profession we treat a lot of problems associated with the lower limb, which is why we are well qualified to help you to keep moving and prevent or treat your blisters.