Bulla
Pronunciation: BUL-ah (plural: BUL-ee)
A large fluid-filled blister measuring more than 10 mm in diameter, representing a primary skin lesion seen in conditions such as pemphigus and bullous pemphigoid.
Full Definition
A bulla (plural: bullae) is a circumscribed, elevated lesion containing serous or seropurulent fluid and measuring more than 10 mm in diameter. It is distinguished from a vesicle solely by size. Bullae arise from separation at various levels of the epidermis or dermo-epidermal junction, which determines the underlying diagnosis. They are hallmark findings in autoimmune blistering disorders such as bullous pemphigoid and pemphigus vulgaris. Editors working on dermatology manuscripts must ensure 'bulla' and 'vesicle' are not used interchangeably, as size-based terminology carries diagnostic and coding significance.
Usage
Usage note: Always use the plural 'bullae', not 'bullas'. Do not substitute 'blister' in formal clinical or regulatory writing.
In Context
- "Multiple tense bullae were present on the patient's forearms and thighs, consistent with bullous pemphigoid." — Dermatology case report
- "The copy-editor queried whether the author intended 'vesicle' or 'bulla', as the lesion diameters reported exceeded 10 mm." — Manuscript editing note