Vesicles, Bullae and Blisters Flashcards
What is a blister?
- A fluid filled lesion
- Described as either a vesicle or bullae (depending on size)
What is a pustule?
A lesion filled with purulent material (pus) rather than fluid
What are the characteristics of a Vesicle?
- <5mm
- Fluid filled
What are the characteristics of a Bullae?
- >5mm
- Fluid filled
What types of trauma are aetiologies for blister?
- Mechanical
- Thermal
- Chemical
What types of non-traumatic causes are aetiologies for blisters?
- Infection
- Immunological
- Idiopathic (unknown)
- Genetic
What types of common infections can cause blistering?
- Tinea Pedis
- Impetigo (bacterial infection caused by S.Aureus
- Herpes Simplex
What non-traumatic immunological responses can cause blistering?
- Allergic reaction to insect bite
- Pompholyx
- Pemphigus
- Pemphigoid
- Epidermolysis bullosa
What are clinical presentations of Pompholyx?
- Bubble
- Tiny clear blisters which can cover a large area
- Appear on hands and feet
- Usually itchy

What is Epidermolysis Bullosa?
- A group of connective tissue disorders
- Genetic
- Various types - Simplex, dystrophic, and junctional
- Skin can blister and tear with minimal touch
What type of mechanical trauma would cause blistering?
- Shear stress
What is superficial blistering?
- Blister occurs in s.corneum/granulosum layer
- Superficial acute shearing stress causes breakdown of S.corneum layer

What is intra-epidermal blistering?
- Involves lower layers of epidermis - s.spinosum
- Result of ongoing shearing stress
- s.spinosum has broken down due to stress
- Painful due to fluid filled serum sac pressurising nerve endings

What are sub-epidermal blisters?
- Occurs at dermal-epidermal junction
- Result of excessive and deeper shearing stress
- Epidermis seperates from dermis to form a firmer, raised blister
- Tissue disruption is can be accompanied by a bleed into the serum sac to form a blood blister

What needs to be commented on when recording lesions?
- Location
- Size
- Duration
- Presence of infection?
- Pain
- Discharge
- Appearance
- Odour
- Presence of foreign bodies
What is the Action and Plan part of treating blisters?
- Establish cause
- Should blister be left intact, drained, or de-roofed?
- Offload pressure to reduce shear stress
- Use of dressings
- Patient advice / health promotion
What are the positives and negatives to leaving a blister intact?
-
Positives
- Acts as a natural barrier to infection
- Cytokines / growth factors in blister fluid may help healing process
-
Negatives
- Prolongues inflammatory stage of wound healing
What are the positives and negatives to de-roofing blisters?
-
Positives
- reduces likelihood of wound progression by relieving pressure.
- Provides ability to access wound base
-
Negatives
- Increases risk of infection
When should blsiters be left intact?
- If they are not causing any pain and there are no further complications
When should blisters be drained?
- If you are unable to offload pressure due to the high tension of the blister, meaning rupture would be likelihood anyway outside of hygenic environment
- If infection is present
What is the procedure to drain a blister?
- Irrigate the area (clean with saline solution)
- Use forceps and gauze found in sterile pack
- Disregard gauze and forceps
- Dry area with new forceps and gauze
- Make incision at top and base of blister (blade 15)
- Soak up exudate with sterile gauze
- Cleanse area
- Have area checked
- Dress & Pad
What common dressings can be used for blisters?
- Melolin
- Inadine
- Duoderm