Rosacea is a chronic skin condition characterized by redness and inflammation of the skin, especially on the nose, cheeks, forehead and chin. It can also lead to bumps, pimples, and visible blood vessels on the skin. Rosacea usually affects middle-aged and older people, and women are more commonly affected than men.

The exact cause of rosacea is unknown, but it is believed to be caused by a combination of genetics, sun exposure, inflammation, and bacteria. Rosacea can also be triggered by certain foods, drinks, and medications.

There are several subtypes of rosacea, including:

1. Erythematotelangiectatic rosacea: This subtype is characterized by redness, visible blood vessels, and a burning sensation in the skin.
2. Papulopustular rosacea: This subtype is characterized by bumps and pustules on the skin.
3. Phymatous rosacea: This subtype is characterized by thickening of the skin and enlargement of the nose.
4. Ocular rosacea: This subtype affects the eyes and can lead to dry eyes, burning eyes and inflammation of the eyelids.