AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Friction blisters of the skin commonly occur in active populations. They are the result of frictional forces between the involved skin area and the object with which the skin is in contact. Friction blisters create localized discomfort; however, they should not be taken lightly because secondary impetigo may become a serious complication with resulting cellulitis and sepsis.¹

The bulk of research on friction blisters comes from the military because of the nature of the physical activity involved in this field. Friction blisters have also received much attention in the field of sports medicine.

The eMedicine articles Impetigo and Cellulitis may be helpful, as may the Medscape Exercise and Sports Medicine Resource Center and the Sepsis Resource Center.

Pathophysiology

A frictional force causing friction blisters occurs when the skin is in contact with a surface and an attempt is made to move across the skin with an external force. Frictional force opposes this movement. The influence of epidermal hydration on the friction of human skin against textiles was studied. Increasing cutaneous hydration may cause sex-specific changes in the mechanical properties and/or surface topography of human skin, leading to skin softening and increased real contact area and adhesion.²

Studies involving rubbing the skin with a constant force show an initial slight exfoliation of the skin over the involved area. Focally, mild erythema also develops. The patient may experience stinging or burning, while a zone of pallor develops around the erythematous area. The pallor eventually extends into the region of erythema and this area develops into a blister.

The effect of wearing socks with different frictional properties on plantar shear was studied because this is a possible mechanical risk factor for foot lesion development.³ Wearing socks with low friction against the foot skin reduced the plantar shear force on the skin more than a sock with low friction against the insole.

Mortality/Morbidity

Secondary impetigo may become a serious complication, with the potential for cellulitis and sepsis.

Race

No known predilection is reported for any particular race.

Sex

No known predilection is described for either sex.

Age

No known predilection is apparent for any age group.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• Children often present with poorly fitting shoes and reporting a blister on the heel.
• Friction blisters tend to occur in areas of thick adherent stratum corneum (eg, palms, soles, heels, dorsa of fingers).
• In regions of the body where the stratum corneum is thinner, a repeated friction force causes the stratum corneum to erode, and instead of a blister, an erosion or abrasion occurs.
• The likelihood of forming a friction blister at susceptible sites is based on the magnitude of the frictional force and the number of times an object moves across the skin (ie, shear cycles). Moisture and lubricating substances present on the skin surface are additional factors.
• With a greater frictional force, fewer cycles of rubbing against the skin are needed to produce a blister.
• Moisture on the skin surface may either increase the friction force or, in the case of very moist skin, decrease it temporarily by providing lubrication.
• Lubricating agents also tend to reduce the friction force temporarily at the onset; however, friction tends to increase with prolonged application of the external force.
• Pyogenic granuloma on the hand has been described subsequent to a friction blister in a hand surgeon.⁴

Physical

Discrete bullae formation at sites of trauma is evident.

Causes

Poorly fitting shoes are the most common cause. Heat, sweating, and maceration of the skin may predispose to friction blister formation.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Acquired and hereditary epidermolysis bullosa
Systemic amyloidosis
Coma blisters
Bullous insect bite reactions
Other bullous dermatoses

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Histologic Findings

The friction blister forms with a split in the stratum spinosum. Midepidermal necrosis is evident. The blister roof consists of normal and necrotic keratinocytes; the blister floor consists of normal, edematous, and degenerating keratinocytes. The blister cavity is filled with a clear transudate. High mitotic activity is present in the base of the blister about 30 hours after formation of the friction blister. A significant inflammatory infiltrate is not observed as long as the blister site is not secondarily infected.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical Care

Management of friction blisters includes sterile drainage of the site while leaving the blister roof intact to serve as a dressing. This method helps relieve some discomfort and protects the site from superinfection. A donut of moleskin may also be applied to minimize additional trauma to the blister and to relieve discomfort. If the blister roof is already fully or partially removed, treat the site as an open wound with appropriate antiseptic and surgical bandage application. Hydrocolloid dressings have also been proven to decrease discomfort and encourage healing. Some recommend debridement of the skin of the blister, the use of a topical containing nitrofurazone, and the application of a bandage.⁵

• Prompt attention to friction blisters is important to prevent the development of secondary impetigo with possible cellulitis and sepsis.
• Institute appropriate systemic antibiotic therapy if impetigo develops.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Institute appropriate systemic antibiotic therapy if impetigo develops.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Deterrence/Prevention

• Prevention of friction blisters has focused on antiperspirant agents and appropriate footgear.^{6, 7}
• Antiperspirant agents decrease the likelihood of developing friction blisters, but their use is confounded by a high incidence of irritant contact dermatitis.
• The incidence of friction blisters on the feet may be somewhat decreased by the use of neoprene insoles, acrylic-based socks, or thin polyester socks combined with a thick wool or polypropylene sock that can maintain its bulk in the presence of moisture from sweat and compression.^{8, 9, 10, 11, 12}
• Appropriately fitted shoes also are helpful in the prevention of friction blisters.

Complications

• Impetigo may become a serious complication with resulting cellulitis and sepsis.

Prognosis

• Friction blisters create localized discomfort; however, they should not be taken lightly because secondary impetigo may become a serious complication with resulting cellulitis and sepsis.

Patient Education

• Educate patients about the importance of prevention measures (see Deterrence/Prevention).
• For excellent patient education resources, visit eMedicine's Bacterial and Viral Infections Center and Skin, Hair, and Nails Center. Also, see eMedicine's patient education articles Impetigo, Skin Rashes in Children, and Antibiotics.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Friction blisters in children may be misconstrued as child abuse in some settings. In addition, inadequate measures to prevent friction blisters may lead to loss of a sports event or wartime morbidity.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

1. Hoeffler DF. Friction blisters and cellulitis in a navy recruit population. Mil Med. May 1975;140(5):333-7. [Medline].
2. Gerhardt LC, Strässle V, Lenz A, Spencer ND, Derler S. Influence of epidermal hydration on the friction of human skin against textiles. J R Soc Interface. Mar 10 2008;[Medline].
3. Dai XQ, Li Y, Zhang M, Cheung JT. Effect of sock on biomechanical responses of foot during walking. Clin Biomech (Bristol, Avon). Mar 2006;21(3):314-21. [Medline].
4. Sasmaz S, Karaoguz A, Uzel M, Coban YK. Pyogenic granuloma on the hand subsequent to friction blister in a hand surgeon. Dermatol Online J. 2006;12(3):22. [Medline].
5. Sevilla JA, Rodriguez FM, Dallasta RM. [The treatment of blisters caused by friction while hiking the Road to Santiago]. Rev Enferm. Jan 2007;30(1):32-6. [Medline].
6. Knapik JJ, Reynolds K, Barson J. Influence of an antiperspirant on foot blister incidence during cross-country hiking. J Am Acad Dermatol. Aug 1998;39(2 Pt 1):202-6. [Medline].
7. Reynolds K, Darrigrand A, Roberts D, Knapik J, Pollard J, Duplantis K, et al. Effects of an antiperspirant with emollients on foot-sweat accumulation and blister formation while walking in the heat. J Am Acad Dermatol. Oct 1995;33(4):626-30. [Medline].
8. Jagoda A, Madden H, Hinson C. A friction blister prevention study in a population of marines. Mil Med. Jan 1981;146(1):42-4. [Medline].
9. Knapik JJ, Hamlet MP, Thompson KJ, Jones BH. Influence of boot-sock systems on frequency and severity of foot blisters. Mil Med. Oct 1996;161(10):594-8. [Medline].
10. Smith W, Walter J Jr, Bailey M. Effects of insoles in Coast Guard basic training footwear. J Am Podiatr Med Assoc. Dec 1985;75(12):644-7. [Medline].
11. Spence WR, Shields MN. Insole to reduce shearing forces on the soles of the feet. Arch Phys Med Rehabil. Aug 1968;49(8):476-9. [Medline].
12. Spence WR, Shields MN. New insole for prevention of athletic blisters. J Sports Med Phys Fitness. Sep 1968;8(3):177-80. [Medline].
13. Akers WA. Measurements of friction injuries in man. Am J Ind Med. 1985;8(4-5):473-81. [Medline].
14. Akers WA, Leonard F, Ousterhout DK, Cortese TA Jr. Treating friction blisters with alkyl- -cyanoacrylates. Arch Dermatol. Apr 1973;107(4):544-7. [Medline].
15. Akers WA, Sulzberger MB. The friction blister. Mil Med. Jan 1972;137(1):1-7. [Medline].
16. Darrigrand A, Reynolds K, Jackson R, Hamlet M, Roberts D. Efficacy of antiperspirants on feet. Mil Med. May 1992;157(5):256-9. [Medline].
17. Epstein WL, Fukuyama K, Cortese TA. Autoradiographic study of friction blisters. RNA, DNA, and protein synthesis. Arch Dermatol. Jan 1969;99(1):94-106. [Medline].
18. Herring KM, Richie DH Jr. Friction blisters and sock fiber composition. A double-blind study. J Am Podiatr Med Assoc. Feb 1990;80(2):63-71. [Medline].
19. Hunter JA, McVittie E, Comaish JS. Light and electron microscopic studies of physical injury to the skin. II. Friction. Br J Dermatol. May 1974;90(5):491-9. [Medline].
20. Knapik JJ, Reynolds KL, Duplantis KL, Jones BH. Friction blisters. Pathophysiology, prevention and treatment. Sports Med. Sep 1995;20(3):136-47. [Medline].
21. Rumball JS, Lebrun CM, Di Ciacca SR, Orlando K. Rowing injuries. Sports Med. 2005;35(6):537-55. [Medline].

Article Last Updated: Apr 30, 2008