What Causes Rosacea?
The exact cause of rosacea remains unknown. However, research shows it likely results from a combination of genetic, immune system, and environmental factors working together.
Immune System Problems
People with rosacea have an overactive immune response in their skin. Their bodies produce too many certain proteins called cathelicidins. These proteins normally fight infections, but in rosacea patients, they cause redness and inflammation. The immune system also reacts too strongly to normal skin bacteria and mites.
Demodex Mites
Tiny mites called Demodex live on everyone's skin. However, people with rosacea often have many more of these mites than normal. When these mites die, they release bacteria that trigger inflammation. About 80% of people with papulopustular rosacea (the type with bumps) have high numbers of these mites.
Genetics
Rosacea runs in families. If your parents or siblings have rosacea, you are more likely to develop it. People of Northern European descent have higher rates of rosacea, though it can affect anyone.
Blood Vessel Problems
The blood vessels in rosacea-prone skin don't work correctly. They expand too easily and may not shrink back properly. This causes the lasting redness and visible veins common in rosacea.
Common Triggers
While these factors don't cause rosacea, they can trigger flare-ups. Sun exposure is the most common trigger. Other triggers include hot weather, stress, spicy foods, alcohol, hot drinks, exercise, and wind. Each person has different triggers. Keeping a diary can help you identify yours.
H. pylori Bacteria
Some research suggests a link between H. pylori stomach bacteria and rosacea. This bacteria can trigger immune responses that may worsen skin inflammation. However, study results are mixed, and more research is needed.
The Bottom Line
Rosacea develops from multiple factors working together. Your genes, immune system, skin microbes, and blood vessels all play a role. While you can't change the underlying causes, you can manage triggers and work with a dermatologist to control symptoms.
Frequently Asked Questions
Is rosacea caused by poor hygiene?
Can stress cause rosacea?
Is rosacea hereditary?
Why do Demodex mites cause rosacea?
References
- American Academy of Dermatology. Rosacea: Causes. AAD. [cited December 21, 2025]. Available from: https://www.aad.org/public/diseases/rosacea/what-is/causes
- National Rosacea Society. Causes of Rosacea: Demodex Mites & Microbes. Rosacea.org. [cited December 21, 2025]. Available from: https://www.rosacea.org/patients/causes-of-rosacea/demodex-mites-and-microbes
- Lacey N, Kavanagh K, Tseng SCG. The Pathogenic Role of Demodex Mites in Rosacea. PMC - National Institutes of Health. [cited December 21, 2025]. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC7649190/
- Frontiers in Medicine. Rosacea pathogenesis and therapeutics: current treatments and a look at future targets. Frontiers. [cited December 21, 2025]. Available from: https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1292722/full
Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before starting any new skincare treatment, especially if you have underlying health conditions, are pregnant, or are taking medications.