Vesicle
Pronunciation: /ˈvɛsɪkəl/
A small, fluid-filled blister measuring less than 5 mm in diameter, representing a primary skin lesion.
Full Definition
A vesicle is a circumscribed, raised lesion containing clear serous fluid, by convention less than 5 mm in its greatest dimension. It arises from localised oedema within or below the epidermis and is a hallmark lesion in conditions such as herpes simplex, varicella, pompholyx, and allergic contact dermatitis. Editors must distinguish vesicle from bulla (which exceeds 5 mm) and pustule (which contains purulent rather than serous content). The term appears frequently in lesion description sections of case reports, histopathology summaries, and dermatology examination findings. Consistent application of the size threshold is essential for editorial accuracy.
Usage
Usage note: Do not use interchangeably with 'blister'; 'blister' is the lay term and should appear only in patient-facing documents.
In Context
- "Grouped vesicles on an erythematous base were observed along the T4 dermatome, consistent with herpes zoster." — Case report clinical findings
- "The editor corrected the manuscript, replacing 'large vesicles' with 'bullae' where lesion diameter exceeded 10 mm." — Copy-editing note