BSA
Also written as: BSA — Body Surface Area
Body Surface Area; a measurement used in dermatology to quantify the extent of skin involvement in conditions such as psoriasis or burns.
Full Definition
In medical dermatology, BSA (Body Surface Area) is a clinical metric used to express the percentage of total skin affected by a dermatosis. The 'rule of nines' and the palm-area method (where the patient's palm equals approximately 1% BSA) are standard assessment tools. BSA is used to guide treatment decisions — for example, systemic therapy is often considered when psoriasis affects > 10% BSA. Editors should ensure that BSA is always expanded at first mention in formal documents and that percentage figures are presented consistently (numeral plus % sign without a space in most medical style guides). BSA in oncology carries a different meaning (used for chemotherapy dosing); dermatology editors must confirm context.
Usage
Usage note: Expand at first mention. Confirm dermatology context versus oncology context. Use numeral + % symbol: '10% BSA,' not 'ten per cent BSA.'
In Context
- "Biologic therapy was initiated when the patient's psoriasis exceeded 10% BSA and failed to respond to topical treatment." — Treatment guidelines document
- "The editor expanded 'BSA' to 'Body Surface Area' at first occurrence in accordance with journal style." — Copy-editing log