A chronic skin disease which causes redness over parts of the face, such as the cheeks and nose, but primarily the forehead, the chin, and the lower half of the nose: With rosacea, the tiny blood vessels in the areas of the face enlarge (dilate) and become more visible through the skin, characterized by red or rosy colorations like tiny red lines or the appearance of acnelike pimples.

Increased conditions of acne rosacea can be prevented by avoiding certain foods, alcohol, caffeine, and exposure to sunlight, extremes of temperature, wind, and certain cosmetics as prescribed by a dermatologist.

In the earlier stages of rosacea, the patient may notice gradual reddening of the skin, often mistaking these changes for acne, sunburn, or dermatitis.