Friction Blisters Workup

Updated: Apr 06, 2021
  • Author: Robert A Schwartz, MD, MPH; Chief Editor: Dirk M Elston, MD  more...
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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.