What is the root cause of rosacea?

What Is the Root Cause of Rosacea?

Living with rosacea can mean constant redness that flares up at the worst moments. Many people try skincare routine after skincare routine for relief, but without understanding what’s actually causing the condition, results are often temporary and frustrating.

Researchers haven’t identified one single cause of rosacea, but several contributing factors are well established: abnormalities in the blood vessels that lead to redness, an overactive immune response, microscopic mites that live on the skin, and a genetic predisposition. Understanding these mechanisms is essential for effective, personalized treatment. Let’s look at each one.

Blood Vessel Abnormalities

A key factor in rosacea is the abnormal behavior of facial blood vessels. In people with rosacea, the vessels react, dilating more easily than in other people. This constant dilation produces persistent redness and flushing.

Erythema, the redness rosacea is known for, is because of this vascular sensitivity. Managing it involves a combination of identifying what causes the reaction and medical treatments. These include topical medications or lasers.

Microorganisms: Demodex Mites

Certain microorganisms, particularly the mite Demodex folliculorum, are found in greater numbers on the skin of people with rosacea. These mites live in hair follicles, and when they are high in numbers, they can trigger inflammation. As the body responds, an intensified immune reaction may follow, worsening rosacea. The relationship between Demodex and rosacea is complex, but it shows how visible symptoms often come from deeper causes.

Inflammatory Proteins

Research has found that people with rosacea tend to have elevated levels of cathelicidins, proteins that play a central role in the skin’s immune response. While cathelicidins are meant to help defend against threats, in rosacea they appear to contribute to the redness, swelling, and pustules that characterize flare-ups, intensifying the inflammatory process.

Blood vessel abnormalities, Demodex mites, and inflammatory proteins don’t act in isolation, genetics and immune function play a role.

The Role of Genetics and Immune Response

Rosacea does appear to run in families. Studies show that people with a family history of rosacea are more likely to develop it themselves. Individuals with rosacea are four times more likely to have a family history of the condition compared to those without it. Family history rates among rosacea patients range from about 40% to 50%. A twin study similarly found that genetics accounts for a substantial share of rosacea risk, with environment contributing the rest.

Ancestry appears to matter too, surveys have found rosacea to be especially prevalent among people of German, Irish, and English descent, suggesting a link between genetic heritage and susceptibility. The specific genes involved are still being investigated.

Alongside genetic predisposition, many people with rosacea show signs of an overactive immune system, which can produce excess cathelicidin, the same peptide mentioned before. In someone without rosacea, this peptide helps fight off microbial threats. In rosacea, elevated levels appear to drive inflammation instead.

Understanding your own genetic and immune risk factors, including whether rosacea runs in your family, can help guide more informed conversations with your dermatologist about a treatment plan suited to your specific case.

Learn more about rosacea treatment options tailored to your skin.

Frequently Asked Questions

What role does the skin’s immune response and inflammation play in rosacea?

The immune response and inflammation are central to rosacea. The condition involves an exaggerated immune reaction to internal and external stimuli, leading to chronic inflammation, flushing, redness, and the formation of papules and pustules.

Elevated levels of specific inflammatory markers, including cathelicidins, have been found in the skin of people with rosacea, helping explain why symptoms can worsen over time.

How does genetics influence the likelihood of developing rosacea?

Genetics plays a meaningful role, around 40–50% of people with rosacea report a family history of the condition, and twin studies suggest genetics accounts for close to half of overall risk. Certain inherited traits affecting skin sensitivity and immune response appear to make some people more susceptible than others.

Is there pain associated with rosacea?

Rosacea is not typically painful, but many patients experience burning, stinging, or occasional itching, particularly during flare-ups.

Is rosacea a skin infection?

No. Although antibiotics are sometimes used in treatment, rosacea is not an infection, it’s a chronic inflammatory condition.

Can menopause affect rosacea?

Yes. The decline in estrogen and progesterone during menopause can worsen rosacea symptoms for some patients, likely due to the hormonal influence on blood vessel behavior and inflammation.

What current research is being done on rosacea’s underlying mechanisms?

Current research is focused on the skin microbiome, inflammatory pathways, and genetic factors. Scientists are studying altered microbial populations in rosacea patients and how immune cells in the skin respond to various triggers, aiming to develop therapies that address root causes rather than just visible symptoms.

If your rosacea symptoms are affecting your daily life, understanding the underlying cause is the first step toward a treatment plan that actually works for your skin. Dr. Debra Jaliman diagnoses and treats all rosacea subtypes at her Upper East Side practice, learn more on the rosacea treatment page.