The exact cause of rosacea is unknown, but it is believed to result from a combination of genetic, immune system, and environmental factors. Key points include:
- Genetics and Immune System: Rosacea may involve an overactive immune response. A protein called cathelicidin, which normally protects the skin from infection, is found in abnormal forms or amounts in people with rosacea, potentially causing inflammation, redness, and swelling
- Demodex Mites: People with rosacea often have higher numbers of Demodex folliculorum mites on their skin. These microscopic mites may trigger an immune reaction that contributes to inflammation. It is unclear whether the mites cause rosacea or are more abundant because of the condition
- Bacterial Factors: Certain bacteria, such as Bacillus oleronius (associated with Demodex mites) and Helicobacter pylori (found in the digestive system), have been suggested to play a role by stimulating inflammation or blood vessel dilation, though definitive links are not established
- Environmental Triggers: Various external factors can provoke or worsen rosacea symptoms by triggering inflammation or blood vessel dilation. Common triggers include sun exposure, extreme temperatures, hot drinks, spicy foods, alcohol (especially red wine), emotional stress, and certain medications
- Neurovascular Dysregulation: Recent research indicates that abnormal regulation of blood vessels and nerves in the skin contributes to flushing and persistent redness in rosacea
- Other Factors: Small intestinal bacterial overgrowth (SIBO) has been linked to rosacea in some studies, suggesting gut bacteria may influence the condition
In summary, rosacea likely arises from a complex interplay of genetic predisposition, immune system abnormalities, microbial factors (mites and bacteria), and environmental triggers that lead to chronic inflammation and vascular changes in the skin
