Blisters

Blisters (sores, ulcers) are an accumulation of liquid under the outermost layer of skin. While this layer is not damaged, the layers of skin below it are. This creates a sac, which can be very painful. We distinguish between different types of blisters, which have different causes. For example, there are pressure ulcers, scalds and blood blisters. A pressure ulcer, also called a water or friction blister, is the most prevalent and well-known type. A pressure ulcer is characterised by the clear colour of the liquid in the sac.

Excessive friction can have multiple causes, such as poorly fitting footwear and/or socks or extended hiking without training. Blisters often occur on the feet of people who play sports. Blisters can occur due to excess friction, as well as due to medication or underlying conditions, such as diabetes mellitus. In these cases, blisters may occur without friction or pressure. In this article, we only discuss blisters caused by pressure or friction. If you suddenly experience a blister without apparent reason, we advise you to please contact your General Practitioner. Blisters can feel unpleasant but are generally harmless. An exception to this rule is if you get blisters as a patient of diabetes mellitus. In this situation, the blister should always be treated by your medical pedicurist. A blister that breaks may become infected. That is why we never recommend simply puncturing a blister.

A blister under your foot or on your foot is the skin’s natural response to excess friction. The chance of blisters increases if the skin is wet. It starts with a red spot. If the source of the friction is not removed, the spot turns into a sac with liquid. The bottom layer of the skin turns into a sort of ‘open wound’. Within 24 hours, a new bottom skin layer is created. That is why it is important not to puncture your blister within the first 24 hours. Waiting 24 hours prevents an infection and speeds up your recovery. However, you may experience pain and discomfort while walking with a blister. Strictly speaking, scalds are second-degree burns and should not be punctured. In the event of a scald, please consult your General Practitioner. A blood blister is the most painful type. They are also difficult to treat. They are similar to pressure ulcers but are located deeper in your skin. They pass through a blood vessel, filling the sac with blood. You should never puncture a blood blister. The risk of infection is high and the blister may bleed uncontrollably.

A pressure ulcer on your foot is characterised by:

A painful red spot/sac on the foot (filled with clear liquid) Pain when moving or walking due to pressure of your shoe or sock The blister may burst by itself and leak liquid

There are multiple factors that (together) lead to a blister on your foot. Friction, cold, heat and moisture all speed up the process. Underlying conditions or medication can also lead to blisters. Continuous ‘rubbing’ of the skin against a shoe or sock creates heat. This change in temperature can weaken the links of your skin layers. This leads to cavities that fill up with liquid; this is a blister. Your foot temperature is often higher during summer. Especially if you have poorly ventilating shoes. A warm skin has higher odds of blisters. But cold feet also have an increased risk, due to reduced   

Too tight or too loose (sports) shoes Non-fitting (sports) socks or a sock seam Sand or a small rock in your (sports) shoe Continuous toe rubbing Wearing a shoe form that does not fit the shape of your foot

You can prevent a blister from occurring by wearing properly fitting shoes and socks (preferably without seams). Do you play sports? Blisters often occur at the start of the season. The skin of your feet has not been exposed to pressure or friction for some time. Please make sure to take protective measures in this period. You can do so by taping the sensitive areas of your skin during trainings and matches, using sports tape or medical tape. Make sure the tape cannot curl up. To prevent blisters, your sports shoes should be the right size. If you like to hike or run, please be careful with preventively taping the feet. During long distances, your feet warm up and the tape may become the cause of blisters. Good fitting sports shoes and sports socks are the best measure under these conditions.

A blister does not always require treatment. If the blister does not hurt or discomfort you, it is best to leave the skin intact. The blister will dry up by itself. However, if you experience much discomfort, we advise you to visit a pedicurist or medical pedicurist. In the event of lasting pain due to a blister, the pedicurist may decide to open the blister. This is only an option for blisters caused by excessive friction and if there are no underlying conditions. To prevent infection, the area around the blister is disinfected. The pedicurist then makes a small incision with a sterile knife and the liquid is pressed out of the blister with a sterile gauze. The liquid should be completely removed from the blister, so that it dries up and the skin can recover. To prevent the risk of infection, the loose skin should not be removed. The blister should then be taped off with overlap to create a ‘tile-effect’, using skin-friendly materials. Any pain will fade shortly after. Never simply puncture a blister. If you would like to prevent friction at sensitive spots or release the pressure and pain of a blister, please cover it with a blister bandage. Blister bandages are available at almost every grocery store and pharmacy. Blister bandages work preventively and should not be used if a blister is already present. Blister bandages should not be used if you have at-risk feet.

Given sufficient opportunity, your blood blister will heal by itself. Please follow the tips below:

Cooling: hold the spot under cold water or under a towel with ice. Cooling the blood blister does not speed up recovery, but it does relieve the pain somewhat. Pressure: applying pressure on the blood blister reduces the swelling. Blood can no longer leak out of the blood vessel and cause the blister to swell. You can apply pressure on the blood blister with a compression bandage or by pressing on the spot with the palm of your hand. Bandage: apply a clean bandage at least once a day or put on a clean band-aid. If necessary, do so more times a day.

People who exercise or play sports can visit the medical sports pedicurist at ProVoet for treatment and advise. Do you have at-risk feet? Please schedule an appointment with the medical pedicurist for treatment of your blisters.