Blisters between the toes (interdigital blisters) can be the most painful blisters of all. There are two types of blisters that could be classed as interdigital blisters: True interdigital blisters – blisters literally between two toes. These aren't as common as the next type - pinch blisters.
Pinch blisters – blisters towards the bottom or end of the toe, common with adductovarus (curly) toes. Click the photo to enlarge. These are a result of how one toe curls under the next toe and basically gets 'trodden on' with a blister being the result.
Following is an explanation of the bony anatomy of the toes. And 7 ways to prevent blisters between toes.
Phalanges - toe bone anatomy
Toes are bony little things. There are 3 phalanges (toe bones) in each toe (except the big toe which has 2, like your thumb). Phalanges aren't smooth straight bones, they're pretty lumpy. Look at the x-ray of the big toe and second toe. In this image you can see the soft tissue of each toe and even the nails if you look closely. And you can see the phalanges under the skin. Notice how they are wide at the ends and skinny in the middle.
Even at the best of times, you can see how the bony prominence of one toe can press on the bony prominence of the adjacent toe. This is even moreso when a toe is bent or curly - one gets "trodden on" and pinched. And toes don't remain still in the shoe as you walk and run. They move relative to one another.
Before we delve into ways you can prevent blisters between toes, both interdigital blisters and pinch blisters, have a look at the true interdigital blister below.
How To Stop Blisters Between Toes
1. Foam or gel wedges
Foam and gel wedges keep the toes physically separated and cushion bony prominences. The material of the wedge absorbs much of the blister-causing shear, particularly the gel material. Interdigital wedges are almost always comfortable because the material is soft and they are relatively thick. But they can dislodge easily - apart from the toes sitting close together, there's nothing actually holding them there. And in-shoe conditions (sweat / grit) cause them to degrade fairly quickly, especially with rigorous activity. These products are available at pharmacies and at some podiatrists.
2. Silicone gel toe sleeve
These are like a little sock for an individual toe and the better ones are elasticised. They offer less cushioning bulk (just because the bit between the toes is thinner) but the upside is they are more likely to stay in place because they are elasticised. They can be quite helpful for pinch blisters as the elasticity encapsulates and holds the soft tissue component of the toe together so it’s not getting "trodden on" as much with each step. But depending on your activity, they will get pretty sweaty and degrade over time, just like the wedges. Applying talcum powder to silicone devices after washing and drying will improve longevity.
3. Otoform K wedge
Otoform K is a mouldable putty material that sets and holds its shape. Podiatrists use it frequently to achieve an even pressure along the entire interdigital space, in spite of even the most significant toe deformities. It's the best way to achieve even pressure - better than cushioning methods (above). The aim is not to straighten the toe as this would prove uncomfortable (and probably wouldn't work anyway), the aim is to avoid focal high pressure. It's best to have the material set while standing - because nonwieghtbearing toe alignment is always different to weightbearing alignment. The good thing about Otoform K is its long-lasting (months to years) and is easy to keep clean. However, they aren’t always tolerated because they can feel hard and foreign.
Tape can be used to reposition a toe, to encapsulate the soft tissue of the toe or just to protect the skin from rubbing. To reposition a toe eg: a curly toe that tucks in & under the next toe, you can tape it up & out so that it sits a bit straighter. But tape stretches and/or comes loose over time so it requires reapplication each day or sometimes several times a day depending on your activity. For toes that suffer pinch blisters, often the fleshy underside of the toe is misshapen to the point where it can be almost triangular! Anything that can hold this soft tissue in, means there’s less toe that the next toe can tread on – and that means less blisters. Here's a video on toe taping technique by Anna Beetham that may help.
Lubricants reduce friction and therefore blister-causing shear. There are many athletes that use lubricants successfully for interdigital blisters. There are a few things to be aware of though. Research shows that the coefficient of friction increases above baseline measures 1-3 hours after it is applied. So after 1-3 hours you should stop and reapply or not only is your blister protection gone, you're actually more likely to get blisters. And oily lubricants can lock sweat within the skin and cause maceration. If you'd like to try a lubricant for interdigital blisters, read this article outlining potential problems with lubricant use first.
Toe-socks add a little more bulk to the interdigital space so they work a bit like a thin wedge or separator by cushioning. This may or may not be enough to stop blisters. They also work like a double-sock system by forming an additional interface (sock-sock). But double-socks rely on different materials being used for friction-reducing properties and this is not the case with toesocks – it’s the same material on each side. But again, this small difference may be enough to stop blisters.
The most common brand of toe-socks are Injinji.
7. Low friction tape on toesocks
Applying an ENGO Patch to toesocks will reduce friction a lot more than the toesocks alone. You'll only need it on one interdigital surface. Remember that foot volume increases the more you are on your feet and active - so don't apply any compression around the toe! Just lay it on and press to adhere. I know of athletes that use duct tape for this application, which may suffice considering any tape will come off when you wash the sock.
Blisters between the toes can be the most painful blisters of all - and they're common. It's no wonder when you consider the anatomy and function of toes and the environment they exist in. How do you stop interdigital blisters?