Blisters Under Your Foot

Causes of blisters under foot

under foot blister

Blisters under the ball of the foot are due to structural (anatomical) issues with your feet.

If the big and little toe joints are contacting the ground before the other middle joints, therefore are subject to an increased amount of pressure. Usually feet with high inside arches are prone to blisters on these outside joints.

If the blister is under the middle joints, they tend to be caused by a structural problem, usually at the big toe joint which isn’t functioning to its full capacity and asking the other joints to work harder. The other smaller joints are not used to such force and blister with the increased shear. The toes can also be clawed making the ball of the foot very prominent and increasing the pressure from the ground.

How to prevent blisters under your foot

Engo patches on the insole of your shoes under where the blister is on the joints, if you are unsure where the joint is in relation to  the insole, then put a fabric plaster on the joint that is affected by the blister, mark it with a permanent marker pen and put your foot back in the shoe, the black marker pen should rub off on to the insole. Accurately marking the area of pressure on the insole,  you can put the engo patch on the marked area on the insole. Make sure that the engo patch is just on the high pressure area, so the other joints can still get traction.

Poron insoles for the whole shoe allows the affected joints to work harder with less pressure from the ground, and less chance of blistering.

Armaskin socks will decrease the shear on that area of the big toe .

Socks  that are moisture wicking and have cushioning  under the sole of the sock  will help with reducing the moisture next to the skin and provide a little cushioning over these joints.

Footwear – running shoes and boots that are designed with a large shock absorbing sole and a slight rocker in the sole of the shoe can help. This means that the big toe joint can drop into the shock absorbing sole without receiving the jamming action from a hard floor surface, allowing the joint to increase its workload, with less pressure applied to it. Less pressure- less shear- no blister formation. Try Hoka One One for this.

Biomechanical Assessment by a Podiatrist may help if all the measures above have failed to resolve the blisters. They will be able to establish why these joints are experiencing an increase of pressure to cause the blister in the first place, the podiatrist may be able to make a simple insole or a prescription orthotic to solve the Biomechanical cause of the blisters. You maybe also experiencing ankle, knee, lower back and sometimes neck pain which could very well be caused by the big joint dysfunction.

Blister prevention Taping with hypafix and KT Pro tape Will reduce the friction to this area

2Toms Blistershield powder can be applied to very specific areas of the skin that are prone to blistering but do not apply all over the underneath of the foot  as it can  cause the foot to loose traction.


What is a blister “hot spot”?

Hotspot – If you have recognised a hotspot on the skin in time before a blister has developed then a simple island dressing will be enough to reduce the shear on the skin and hence reduce the blister from forming further and if you have them, apply an engo patch on the insole as explained in the prevention of blisters. Deflective padding works really well here to reduce the pressure on the joints.

Treating Bubble blisters

Bubble Blister – If the roof is still on then treat it in a similar way to a hotspot on the skin, by applying a sterile island dressing, if the blister bursts (pops) when the dressing is on, then you know the dressing is already sterile and will prevent an infection from getting into the open sore. If you decide to pop the blister, then follow the instruction on “how to pop your blister” and treat it as a roof torn blister. Use an Engo patch applied to the insole with deflective padding applied to the feet.

Treating broken blisters

Roof torn blister – now this type needs its roof (skin) to stay in place, the roof may be broken but your own skin is still important for healing, so use a sterile saline swab to clean the wound first, then apply the povidone iodine stick over the torn area as an antibacterial action and apply a sterile island dressing. A deflective pressure relieving padding as shown in the video to prevent any further pressure and friction.

Treating “popped” blisters

Roof off blister – Hydrocolloid dressing is the only option for this stage of blister, swab the area with saline to make sure the wound is clean and dry before applying the hydrocolloid, add extra hyper fix tape to anchor it down and apply deflective padding if continuing an event or activity. Hydrocolloid dressings are great wound healers and Podiatrists have been using them for a long time in the management of ulcers, with great success. They are not used at any other stage of the blister treatment and can cause blisters if not applied at the correct stage. I like to use some fleecy foam padding over the dressing as it just gives a bit of cushioning to the blister area, which is always very painful.

Treating infected blisters

Infected blister this is the stage of blister that you need to recognise quickly, a bacterial infection has invaded the blister and it could look red, swollen, there may be yellow or green pus in the blister and it could smell? Extending into the skin around the blister might be red and hot with red lines tracking away from the blister. You may feel unwell in yourself and swing from having the chills or feeling quite feverish. This is the time to get medical help as the infection can easily travel into the blood stream causing the infection to move into the leg and cause sepsis.