Learn about acne, including how it is diagnosed and treated, and the steps you can take to help prevent outbreaks. ¿Qué es el acné? Es una afección de la piel que ocurre cuando se obstruyen y se inflaman los folículos pilosos por la acumulación de grasa de las glándulas, bacterias y células muertas en los poros. Learn about acne, including how it is diagnosed and treated, and the steps you can take to help prevent outbreaks. Rosacea is a long-term skin condition that causes reddened skin and a rash, usually on the nose and cheeks. Learn symptoms and possible causes. What is acne? It is caused when blocked skin follicles from a plug caused by oil from glands, bacteria, and dead cells clump together and swell. What is acne? It is caused when blocked skin follicles from a plug caused by oil from glands, bacteria, and dead cells clump together and swell. What is acne? It is caused when blocked skin follicles from a plug caused by oil from glands, bacteria, and dead cells clump together and swell. Mụn trứng cá là một loại bệnh ảnh hưởng đến tuyến dầu của da. Những lỗ nhỏ trên da quý vị (lỗ chân lông) kết nối với tuyến dầu dưới da. Những tuyến này tạo ra chất dầu được gọi là bã nhờn. Lỗ chân lông kết nối với các tuyến này bằng một ống được gọi là na What is rosacea? It is a long-term disease that causes reddened skin and pimples, usually on the face. It can also make the skin thicker and cause eye problems. NIAMS offers science-based classroom materials and activities for teachers to build accurate, age-appropriate lesson plans about skin for students in grades 4, 5, and 6.