Erythematotelangiectatic Rosacea

A 38-year-old fair-skinned woman (Fitzpatrick Type I) presents with a 4-year history of progressively persistent central facial redness triggered by hot weather, exercise, alcohol, and spicy foods. Between episodes, diffuse redness persists across her cheeks, nose, and chin. She reports facial stinging and burning with cosmetics but denies any pimples, whiteheads, or cysts. On examination, the structure marked **B** shows persistent non-transient erythema of the central face with numerous fine linear and arborising telangiectasias on the malar cheeks and nasal dorsum. There are no papules, pustules, comedones, or nodules. Which of the following best describes the clinical diagnosis and primary pathophysiologic mechanism underlying the findings marked **B**?