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Three Part Question

In [persons who are at risk for friction blisters] does [the use of antiperspirants] prevent [friction blisters]?

Clinical Scenario

An 18 year girl went hiking for the first time. Unfortunately she had to interrupt the trip because she suffered from several friction blisters on her feet. When arriving at the emergency department with an infected blister, she asks you whether she could use antiperspirants in order to prevent blisters the next time.

Search Strategy

Medline 1966-1 March 2011 using the Pubmed interface: "Blister"[Mesh] AND ("Antiperspirants"[Mesh] OR antiperspirant* OR "Aluminum Compounds"[Mesh] OR "Emollients"[Mesh] OR "Sweat"[Mesh]). 16 hits
Embase and Medline 1947-1 March 2011 via the Embase.com interface: 'blister'/exp AND ('antiperspirant agent'/exp OR antiperspirant* OR 'emollient agent'/exp OR 'aluminum derivative'/exp OR 'sweat'/exp). 78 hits
The Cochrane Library using the Wiley interface: “MeSH descriptor Blister explode all trees” AND Antiperspirant*. 1 hit

Search Outcome

95 papers were found of which 92 articles were irrelevant or of insufficient quality. The remaining 3 papers are shown in the table.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Knapik 1998 United States	667 cadets with with 328 using an antiperspirant (20% aluminum chloride hexahydrate in anhydrous ethyl alcohol) and 339 using a placebo preparation (anhydrous ethyl alcohol) during 5 nights, followed by a 21 km hike	Intervention study (non-randomized controlled trial)	Blister incidence	21% for antiperspirant group and 48% for placebo group (p<0.01)	Not stated if groups were randomized; high rate of noncompliance with the treatment schedule
			Skin irritation after product use	57% for the antiperspirant group and 6% for the placebo group (p< 0.01)
Reynolds 1995 United States	23 healthy men using (1) an antiperspirant (20% aluminum zirconium tetrachlorohydrex glycine concentration plus water) with emollient additives, (2) emollient additives alone (placebo control), or (3) nothing (nontreated), followed by walking on a treadmill in a warm environment	Intervention study (cross-over study)	Blister incidence	Antiperspirant with emollients vs emollients alone: 39% vs 52% (not significant)	Small study
			Irritant dermatitis after product use	No irritant dermatitis observed for neither condition
Darrigrand 1992 United States	16 male soldiers using two types of antiperspirants or nothing, during five days followed by a 1-hour treadmill march in a warm environment	Intervention study (within subjects design)	Blister incidence	antiperspirant 1 (aluminum chlorohydrate): 0% for antiperspirant group vs 50% for control group (statistically significant according to own calculation and discussion of Knapik 1998); antiperspirant 2 (aluminum zirconium tetrachlorohydrex glycine): 18,75% vs 50% (not significant)	No placebo treatment was used; not clear if washing with soap was also performed on control days; small study; some data were reported not to be significant, but in fact are significant after recalculation
			Irritant dermatitis after product use	antiperspirant 1: 43,75% for antiperspirant group vs 0% for control group (p<0.05); antiperspirant 2: 31.25% for antiperspirant group vs 0% for control group (p<0.05)

Clinical Bottom Line

Evidence could not show a significant decrease in blister incidence when antiperspirants together with emollients were used. Evidence suggests a decrease in blister incidence when using antiperspirants alone, however antiperspirant use would also cause skin irritation.

References

1. Knapik JJ, Reynolds K, Barson J. Influence of an antiperspirant on foot blister incidence during cross-country hiking J Am Acad Dermatol 1998, 39:202-6.
2. Reynolds K, Darrigrand A, Roberts D, Knapik J, Pollard J, Duplantis K, Jones B. Effects of an antiperspirant with emollients on foot-sweat accumulation and blister formation while walking in the heat. J Am Acad Dermatol. 1995, 33:626-30.
3. Darrigrand A, Reynolds K, Jackson R, Hamlet M, Roberts D. Efficacy of antiperspirants on feet. Mil Med. 1992, 157:256-9.