Blisters – a common problem with potentially devastating consequences. A blister is a pocket of fluid in the intradermal layers as a result of friction. Without intervention, these pockets of fluid can grow and rupture, exposing the sensitive and unprotected lower dermal layers. The cost of blisters can range from minor inconvenience to severe illness requiring evacuation such as infection, sepsis, gangrene, and osteomyelitis.
As with most wilderness medicine practices, prevention is the cornerstone of management. This involves high quality footwear that has been broken in, great socks, maintaining a dry environment, and daily foot inspection and care. Blisters start as a “hot spot”, which is an area of pain and redness without fluid collection. This is the time when intervention is most effective. If there is a hot spot or small blister, the AWLS recommendation is to stop immediately and manage it with a donut of moleskin, mole foam, and tape. But is this advice backed by any evidence?
A recent review by Worthing et. al attempted to evaluate which blister prevention strategies were most effective. Of 806 papers screened, only 11 met the inclusion criteria (prospective clinical trials, foot blister prevention, wilderness setting). Five of the studies investigated various sock materials and layering systems, four studies analyzed antiperspirants, and three studies evaluated barrier methods. Most of the studies had major methodological flaws and moderate to high risk of bias. Unfortunately, methodological diversity did not allow for a meta-analysis. Two studies, despite risk of bias, did show moderate confidence in the effect of paper tape in blister prevention.
So there you have it. Paper tape looks promising according to this review. As for the other recommendations on blister prevention, most of them appear to be based on case reports, trial and error, personal experience, and/or expert opinion. Unfortunately, it appears that one of the most common problems in the wilderness does not have enough strong evidence to develop robust practice guidelines. Blisters are not going away any time soon. This paper highlights a window of opportunity for wilderness medicine researchers to tackle this problem.
Looking to be better prepared for wilderness adventures? AWLS offers online wilderness medical courses on topics including dive medicine, ebola, mosquito borne illnesses, lightning and ticks. Medical professionals receive CME credit for these courses, but you don’t have to be a medical professional to take the courses.
Medical professionals can also take our one-week hands-on Wilderness Medicine CME courses at locations around the globe. Check them out, and invite a friend.
Alana Hawley, MD, FAWM, DiMM
Wilderness Medicine Fellowship, University of Utah
PGY-5 Emergency Medicine, McMaster University
Worthing, R.M., Percy, R.L., Joslin, J.D. (2017). Prevention of Friction Blisters in Outdoor Pursuits: A systematic review. Wilderness & Environmental Medicine. https://doi-org.libaccess.lib.mcmaster.ca/10.1016/j.wem.2017.03.007