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