What is rosacea? How does it present?

Rosacea, or acne rosacea, is a common skin condition that may affect up to 12% of the geriatric population. The pathogenesis is not understood, but it is known that patients with rosacea have increased blood flow to the skin and are more likely to demonstrate infestation with Demodex folliculorum, the human hair follicle mite (although its relevance to the pathogenesis of rosacea is unclear). Rosacea primarily affects the forehead, cheeks, nose, and chin. The three primary lesions are telangiectasis, sebaceous gland hyperplasia, and acneiform papules and pustules (see Chapter 21). One or more of these primary lesions may predominate in a particular patient.