Topical Corticosteroid
A steroid preparation applied directly to the skin to reduce inflammation, classified into potency grades from mild (Class I/IV) to very potent (Class IV/I, depending on classification system).
Full Definition
Topical corticosteroids (TCS) are anti-inflammatory agents applied to the skin and classified by potency. The UK system uses four classes (mild, moderate, potent, very potent), while the US system uses seven classes (I–VII, where Class I is most potent). Editors must be alert to this directional discrepancy: UK Class I is mild; US Class I is very potent—an error in an internationally distributed document could have clinical consequences. Abbreviated as 'TCS' on second use. Formulation vehicle (cream, ointment, lotion, foam) significantly affects potency and should be specified precisely in clinical documents.
Usage
Usage note: Always specify potency class AND country classification system when used in an international publication, as UK and US systems are directionally inverted. Abbreviate as 'TCS' only after first full use.
In Context
- "A potent topical corticosteroid (mometasone furoate 0.1% ointment) was prescribed for two weeks." — Dermatology prescription record
- "The author cited a US Class I topical corticosteroid; the editor flagged that this denotes very potent, not mild, in the US system—the opposite of UK Class I." — Editorial query on potency classification