Bulla
Pronunciation: /ˈbʊlə/ (singular), /ˈbʊliː/ (plural)
A fluid-filled blister exceeding 5 mm in diameter, the large-lesion counterpart to a vesicle.
Full Definition
A bulla (plural: bullae) is a primary skin lesion defined as a circumscribed, raised, fluid-filled cavity greater than 5 mm in diameter. Bullae may be intraepidermal, as in pemphigus vulgaris, or subepidermal, as in bullous pemphigoid, and this distinction carries significant clinical and editorial weight when describing pathological findings. The fluid content is typically serous but may be haemorrhagic. Editors should note the irregular plural 'bullae' and resist the anglicised 'bullas'. The term is central to the naming and description of bullous disorders throughout dermatology literature.
Usage
Usage note: Plural is always 'bullae', not 'bullas'. Distinguish from vesicle by size: bullae > 5 mm.
In Context
- "Tense bullae on the flexural surfaces of both arms were the presenting feature of bullous pemphigoid." — Inpatient case summary
- "The plural 'bullae' was restored throughout the manuscript where the author had incorrectly written 'bullas'." — Copy-editing annotation