Skin nontumor

Vesiculobullous and acantholytic reaction patterns

Blood blister

Last author update: 1 September 2016
Last staff update: 11 November 2020

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PubMed Search: Blood blister [title]

Narina Grove, M.D., M.A.
Page views in 2022: 2,070
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Cite this page: Grove N. Blood blister. website. Accessed September 21st, 2023.
Definition / general
  • Essentially identical to friction blister with the extension of cytolysis through the basal layer resulting in a hemorrhagic blister
  • Intraepidermal cleavage due to cytolysis and necrosis of keratinocytes in the upper stratum malpighii
Essential features
  • Mechanical blister associated with manual labor
  • Cytolysis extends through the basal layer causing hemorrhage
  • Mostly clinical diagnosis
  • Symptomatic treatment
  • Friction blister: blister caused by shearing force, which subsequently fills with clear fluid
  • Blood blister: blister caused by excessive force, which fills with blood
  • Hemorrhagic bullae: larger blisters (> 0.5 cm), often multiple and associated with underlying disease process and more often deeper (suprabasilar or subepidermal)
ICD coding
  • S90.82 - Blister (nonthermal) of foot
  • Common in athletes, dancers or those wearing poorly fitting shoes
  • Associated with manual labor
  • Hands and feet; sites subjected to repetitive friction
  • Shearing forces within the epidermis cause friction blisters in the areas where epidermis is thick and firmly attached to the underlying tissue
  • Prolonged walking or repetitive actions
Diagrams / tables

Images hosted on other servers:

Friction blister

Clinical features
  • Hemorrhagic blister usually occurring on exposed skin
  • Most commonly occurring on hands and feet
  • Typically, a clinical diagnosis
  • If solitary, diagnosis is usually a simple blood blister, rarely biopsied
  • Multiple blood blisters of unknown origin may indicate an underlying process (see "differential diagnosis" below)
  • Symptomatic treatment
Clinical images

Images hosted on other servers:

Blood blisters

Gross description
  • Cutaneous vesicle or bulla filled with sanguinous fluid
Microscopic (histologic) description
  • Intraepidermal split
  • The roof of the blister is composed of the stratum corneum, variable stratum granulosum and amorphous cellular debris
  • Most of the degenerated keratinocytes are pale and are located at the floor of the cleft
  • The deeper part of the epidermis consists of undamaged cells
  • In severe cases, the cytolysis may extend through the basal layer leading to hemorrhagic blisters
Microscopic (histologic) images

Contributed by Sara C. Shalin, M.D., Ph.D.

Images hosted on other servers:

Friction blister

Electron microscopy description
  • Clumped tonofilaments, intracellular edema, small vacuoles at the cell periphery, areas devoid of organelles
Differential diagnosis

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