Last weekend I worked foot care at the Western States 100 Mile Endurance Run. We had a fairly dry winter with not much snow in the high country and I had heard runners talk of the dust on the trail. Based on that, I did not expect to see high number of runner’s having foot trouble because of maceration.
Working Michigan Bluff aid station, at 55.7 miles, I was surprised by the runners coming in with wet feet, and varying degrees of maceration. For some, it was minor skin softening and maybe a few surface creases. Others had more severe maceration, with creases that were deeper over widespread areas on the bottom of their feet. A few were really bad – deep creases and skin folding over on itself. In extreme cases, the folded skin can split open.
While maceration is commonly caused by stream and river crossings, it also happens when runners pour water over their heads and body and it runs down into their shoes. Feet also sweat a lot, some people’s more than others, and this also can lead to maceration.
I also worked the finish line. There I saw even worst cases of maceration.
Severe maceration can manifest itself as a burning sensation, and the feeling of large blisters all over the bottom of their feet. Taking off the runner’s shoes and socks, we found virtually all of these complaints to be degrees of maceration. Two facts are evident. First, as might be expected, the longer a runner is on the course, the worse the feet can become. Secondly, not changing one’s shoes and socks during the race can magnify the effects of maceration.
The photos here are of one runner. My recollection is this runner finished the 100 miles in about 29 hours. She came into the podiatrity area of the medical tent and could barely walk. This is not uncommon. Runners dig deep and finish on adrenalin and then once they stop, the extent of the injuries to their feet hits them.

Photo 1 shows the bottom of the right foot – it’s worst than the left. You can see the white of the skin, and the creases running over much of the foot. The creases extend down to the mid-foot. Notice the white skin flap on the tip of the little toe.

Photo 2 is a close up if the toes. You can see the large skin flap on the little toe. This flap of skin was very white and looked as if the skin on the tip of the toes had been pulled outward and pinched. It was about ¼ inch in length. It runs from the toenail to the bottom of the toe.

Photo 3 shows the side of the forefoot. You can see the large fold of skin of the inside of the ball of the foot. This can be very painful and can split open under pressure.
Unfortunately, there is no quick fix for maceration. Typical treatments include warming the feet, moisture-absorbing powder, dry socks, allowing the feet exposure to air to dry, and time. In talking to this runner, she did not change her shoes nor socks during the 100 miles. I don’t recall the type of shoe, but my guess is that it did not allow water to drain.

There are several ways to manage possible maceration. Several years ago I watched as an adventure racer coated the bottom of his feet with Hipoglos, a European version of zinc oxide. The compound helps control moisture on the skin, whether zinc oxide or Desitin or a similar product. RunGoo, Century Riding Cream, and Blue Steel Sports Anti-Chafe Cream are similar products. I may have another product to announce early next month.
Another helpful tip is to make sure your shoes drain well. Whether that means mesh uppers, mesh or a draining material down to the shoes upper sole, or making drain holes with a heated nail, draining water out of the shoe is important. Then of course, changing your shoes and socks is also important. Most 100’s have aid stations with drop bags and it’s easy to put a pair of shoes in one or two drop bags, or have your crew have them ready.
Maceration can be cruel. It ruins the race for some runners. It’s painful. It can take days to heal fully. But there are ways to minimize its effects. If you are running a 100 or a multi-day race, and there is a chance of water on the course, plan accordingly.