What is the name and cause of a wound resulting from a blister on the arm?

Friction Blisters: Cause and Classification

Friction blisters are caused by excess frictional trauma to the skin and are classified as superficial wounds when they do not extend below the dermis layer. 1

Cause of Friction Blisters

• Friction blisters result from mechanical separation of epidermal cells at the level of the stratum spinosum due to frictional forces 2
• Blisters form when shearing forces cause skin components to separate, creating a space that fills with fluid 1
• Factors that increase blister formation include:
  • Moist skin conditions (increases friction) 2
  • Warm environment 3
  • Areas with thick horny layer tightly attached to underlying structures (e.g., palms, soles) 3, 2
  • Vigorous activity and carrying heavy loads 2

Classification of the Wound

• This type of wound is classified as a "superficial ulcer" when structures below the dermis layer are not affected 1
• In traditional nomenclature, this would be considered a "blister" rather than an "ulcer" 4
• When symptomatic bullae (blisters) or erosions are present, they are categorized based on body surface area (BSA) affected:
  • Grade 1: Asymptomatic or blisters covering <10% BSA with no associated erythema 1
  • Grade 2: Blisters covering 10-30% BSA or affecting quality of life 1
  • Grade 3: Skin sloughing covering >30% BSA with associated pain 1

Management of Friction Blisters

• The recommended approach for intact blisters is:
  • Lance/puncture the blister at its lowest point using a sterile needle to facilitate fluid drainage 1
  • Keep the overlying skin as a biological cover 5
  • Apply a clean occlusive dressing with antibiotic ointment 6
• For friction blisters specifically:
  • Draining intact blisters while maintaining the blister roof reduces discomfort and infection risk 2
  • Hydrocolloid dressings can provide pain relief for deroofed blisters 2
  • Monitor for signs of infection (increasing pain, redness, swelling, purulent discharge) 6

Prevention Strategies

• Properly fitting shoes that are broken in slowly 3
• Protective padding over potential blister sites 3
• Wearing appropriate socks (acrylic or polyester/wool combination) 2
• Closed cell neoprene insoles may help reduce foot blisters 2
• Gradual exposure to repeated low-intensity friction can lead to skin adaptations that reduce blister likelihood 2

When to Seek Medical Attention

• If signs of infection develop (increasing pain, redness, warmth, swelling, purulent discharge) 6
• If systemic symptoms occur (fever, chills, lymphadenopathy) 6
• For blisters in critical areas or in patients with compromised immune status 6