Psoriatic Plaque
Pronunciation: sor-ee-AT-ik
The primary lesion of plaque psoriasis: a well-demarcated, erythematous, raised area of skin covered with silvery-white scale.
Full Definition
A psoriatic plaque is a chronic, well-defined, erythematous plaque surmounted by adherent, silvery-white (micaceous) scale, arising from the abnormally rapid proliferation and incomplete differentiation of keratinocytes driven by immune dysregulation. Plaques are most commonly located on extensor surfaces, the scalp, and the lumbosacral region. The Auspitz sign (pinpoint bleeding on scale removal) is characteristic. Editors should hyphenate 'psoriatic' only when it serves as a compound modifier preceding a noun (e.g., 'psoriatic-plaque response'). The entity appears in PASI scoring documents, biologic therapy authorisations, and treatment outcome reports.
Usage
Usage note: Distinguish 'plaque psoriasis' (the disease subtype) from 'psoriatic plaque' (the individual lesion). Both constructions are valid but serve different editorial purposes.
In Context
- "Significant clearance of psoriatic plaques was observed at the 16-week biologic therapy review." — Biologic treatment review letter
- "The psoriatic plaque on the patient's elbow was measured and photographed for PASI scoring." — Clinical trial documentation