The well-known retail example of a hydrocolloid dressing for blisters is Compeed.
Another is Band-Aid Advanced Healing.
I use a clinical version called Duoderm or Comfeel.
For deroofed blisters only
Hydrocolloid dressings should only be used on deroofed blisters - blisters where the roof has been removed, leaving a red raw sore. Something like this (below).
As the raw blister base heals, it weeps. This weepiness combines with the dressing to provide the best environment for healing. And it prevents the dressing from sticking to the raw wound. That way it won't disrupt valuable healing tissue.
Do not use hydrocolloids on blisters with an intact or torn roof!
If you put hydrocolloids on a blister with an intact or torn roof, they will rip the blister roof off upon removal.
How to use hydrocolloids successfully
Hydrocolloid dressings are a must in the healing of deroofed blisters. But they suffer a poor reputation, as highlighted below:
"My crew have had a high number of bad experiences with Compeed. For a long duration event, it’s a nightmare to remove. And it usually brings a sizeable chunk of skin with it, unless removed with great patience and dexterity."
"My team have dealt with hundreds of cases of Compeed that has almost morphed into "one" with the skin. It's really difficult to see where the Compeed finishes and where the skin begins. We actually recommend against it for long events for that reason. And if we see it in use, we speak up and discourage it."
"Personally, my worst blister treatment experiences of all time have been removing this partially metamorphosed Compeed from badly blistered feet."
"The open skin under the dressing stinks and the skin goes all wrinkly."
I completely understand these concerns. I've witnessed them myself, many times. Here's an example (below).
This was from the 2015 ANZAC Ultramarathon in Canberra. This runner had applied Compeed when he saw a blister forming. The blister roof was intact at the time. Later, as he removed his sock, he realised the Compeed had melded with the sock and he couldn’t get the two apart. He also couldn't peel the Compeed from his blister. So as he took his sock off, the Compeed ripped the blister roof off.
If you've had a bad outcome with Compeed, there are three potential reasons why. I'm pleased to say, each is easily avoided.
1) Hydrocolloids are not for blister prevention
There is an expectation that the hydrocolloid dressing alone will prevent a blister from developing and/or prevent it from getting worse. This expectation is wrong. Don’t use hydrocolloids for blister prevention – they are a blister treatment.
2) Only use hydrocolloids on deroofed blisters
Hydrocolloid dressings have an adhesive which make them stick. For this reason, do not put them on a blister with its roof intact, or with its roof torn. It will tear the roof off when you come to remove the dressing. Hydrocolloids need a weepy wound base to work their magic. The weepy stuff does two good things:
- It prevents the dressing from sticking to that part of the skin
- It partially dissolves to provide a gel that promotes healing
In my university days (some 25 years ago now) I was on the grinder doing some heavy orthotic modifications when my hand slipped and the grinder took a nasty gouge from my knuckle. I grabbed some Duoderm from the student clinic and used it as directed until it was healed. Within a week or so, the deep gouge had filled in and there was a nice pink area of healed skin in it's place. Not only that, the skin remained flexible enough so as not to limit flexion in the finger during and after healing - something that wouldn't have happened if I'd allowed the wound to dry out and scab over. It was remarkable. I still have a scar but it is quite underwhelming considering the size of the initial injury. If you don't believe me, the next time you have a weepy wound, get one of these dressings and try it.
3) Don't expect hydrocolloids to stay on, on their own
Although hydrocolloids have an adhesive to make them stick to the skin, I don't expect it to work on feet - not well enough. On your arm, fine. On my finger, fine. But on your feet, not fine. Think about the in-shoe environment - it's sweaty in there, and that's a constant threat to adhesion. All it takes is for one edge of the dressing to roll-back a little and be exposed to the sock (annoyingly, it will stick like glue to the sock - see photo above).
I recommend Fixomull around the circumference of a hydrocolloid dressing. Leave the majority of the dressing area visible – we need to visualise the degree of weepiness to determine when to change the dressing. Plus, hydrocolloids allow wound gasses to evaporate through the dressing (whilst being waterproof from the outside).
How long do you leave it on for?
Good question. Hydrocolloids can be left on for a few days or even a week. It all depends on how weepy the wound is. It can take a bit of practice to get this right. You don't want it on for a week if your deroofed blister is very weepy because you'll run the risk of the surrounding skin getting macerated (water-logged, white, rubbery). But there's nopoint removing it if the weepiness is only light. The weepy gel-like substance under the dressing will track toward the edge of the dressing with time. It might take 12 hours or it might take a week, but when it gets to the edge of the dressing, change it.
For more information
Written by Rebecca Rushton
Rebecca is an Australian podiatrist with over 20 years experience. She has spent a lifetime dealing with her own blister prone feet in her sporting and everyday life. Rebecca specialises in helping athletes and sports medicine professionals figure out how to manage foot blisters with ease. And for kicks, she enjoys providing blister care at multiday ultramarathon events.
Rebecca is the founder of Blister Prevention and author of "The Blister Prone Athlete's Guide To Preventing Foot Blisters".