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Rosacea: Causes

If you’ve been diagnosed with rosacea, you may be wondering what causes it and why you developed it. Here’s what we know.

What causes rosacea?

Exactly what causes rosacea is unclear. However, scientific breakthroughs, many made by dermatologists, are giving us a better understanding of what may be happening inside the body.

It’s possible that the many signs and symptoms of rosacea, which include flushing, acne-like breakouts, and eye problems, are due to inflammation.

The inflammation could explain why rosacea begins with flushing that can become a persistent color and why signs like acne-like breakouts develop. As the inflammation increases so do the signs and symptoms.

What causes this inflammation? We know that inflammation is a key part of the body’s ability to fight off infection and heal injuries. This means that the immune system activates cells that lead to inflammation.

It may be that when someone has rosacea, the immune system is set off by rosacea triggers like sunlight, heat, or spicy foods.

Here’s what else may be going on in the immune system to cause rosacea:

  • A protein in the immune system that normally protects the skin from infection, cathelicidin, may cause the color change (red on lighter skin and violet or brown on darker skin tones) and swelling. How the body processes this protein may determine whether a person gets rosacea.

  • Mites that live on nearly everyone’s skin may play a role. Called Demodex, these mites are too tiny to be seen without a powerful microscope. However, researchers have found that these mites often appear in greater numbers when someone has rosacea. It’s possible that the larger number of mites triggers an immune response that leads to inflammation, which causes rosacea.

  • A bacterial infection may play a role. When someone develops a bacterial infection caused by H. pylori, this infection can stimulate the immune system and cause inflammation. Researchers have found when someone with rosacea has this type of infection, treating the infection may calm rosacea. However, other studies have found that treating the infection did not help. More research is needed.

Researchers are also looking at the possible roles that the nervous and circulatory systems may play a role in causing rosacea.

Why do some people develop rosacea?

There’s no clear-cut answer as to why one person develops it, and another doesn’t. However, research shows that women develop rosacea more often than men.

The likelihood of developing rosacea also seems to increase if you one or more of the following describe you:

  • 30 years of age or older

  • Fair-skinned, and have blonde hair and blue eyes

  • Have a blood relative who has/had rosacea or severe acne

  • Had lots of acne breakouts — or acne cysts and/or nodules

  • Going through menopause

If none of the above traits apply, you can still develop rosacea. Millions of people have this condition.

Dermatologists are increasingly diagnosing rosacea in people who are of Asian, Latin American, or African ancestry. People younger than 30 also develop it. While rare, children get rosacea.

If you think you may have rosacea, getting an accurate diagnosis and treatment are important. Treatment can help you feel more comfortable and prevent rosacea from worsening. To find out how dermatologists diagnose and treat rosacea, go to Rosacea: Diagnosis and treatment.

Alexis AF, Callender VD, et al. “Global epidemiology and clinical spectrum of rosacea, highlighting skin of color: Review and clinical practice experience.” J Am Acad Dermatol. 2019 Jun;80(6):1722-9.e7.

Forton FMN. “The pathogenic role of Demodex mites in rosacea: A potential therapeutic target already in erythematotelangiectatic rosacea? Dermatol Ther (Heidelb). 2020 Dec;10(6):1229-53.

Gallo RL, Granstein RD, et al. "Standard classification and pathophysiology of rosacea: The 2017 update by the National Rosacea Society Expert Committee.” J Am Acad Dermatol. 2018 Jan;78(1):148-55.

Sanz J, Gao JL, et al. “Prevalence of rosacea in transgender and gender-diverse populations: a retrospective cohort study.” Br J Dermatol. 2023 Feb 10;188(2):304-306.

van Zuuren EJ, Arents BWM, et al. “Rosacea: New concepts in classification and treatment.” Am J Clin Dermatol. 2021 Jul;22(4):457-65.

Yang X. “Relationship between Helicobacter pylori and rosacea: Review and discussion.” BMC Infect Dis. 2018 Jul 11;18(1):318.

Written by:
Paula Ludmann, MS

Reviewed by:
Elan M. Newman, MD, FAAD
Rajiv I. Nijhawan, MD, FAAD
Brittany Oliver, MD, FAAD

Last updated: 4/3/24