The exact cause of rosacea is unknown. However, most experts believe it may be caused by a number of related factors. These are outlined below.
Blood vessel abnormalities
Many dermatologists (skin specialists) believe that abnormalities in the blood vessels of the face may be a major contributing factor for rosacea. This may explain the symptoms of flushing, persistent redness and visible blood vessels. However, it is not known what causes these abnormalities.
Demodex folliculorum
Demodex folliculorum is a microscopic mite (tiny insect) that may contribute to rosacea. These mites usually live harmlessly on human skin, but higher numbers of mites have been found on people with rosacea. However, it is uncertain whether the mite is a cause or an effect of rosacea.
Helicobacter pylori bacteria
Helicobacter pylori bacteria, which are found in the digestive system, have been suggested as a possible cause of rosacea, although the link is not proven. The bacteria may stimulate the production of a protein called bradykinin, which is known to cause blood vessels to expand.
Genetics
Rosacea seems to run in families. However, it is not known which genes are involved or how they are passed on.
Triggers of rosacea
Most people who have rosacea notice that certain triggers make their symptoms worse. Different people can have different triggers, but the most commonly reported ones include:
- exposure to sunlight
- stress
- hot weather
- exposure to wind
- strenuous exercise
- alcohol
- hot baths
- cold weather
- spicy foods
- humidity
- caffeine (found in tea, coffee and cola)
- dairy products
- acute (short-term) medical conditions, such as a cold or fever (high temperature)
- chronic (long-term) medical conditions, such as high blood pressure (hypertension)
- vasodilatory medicines, which are often used to treat high blood pressure
