What is rosacea?
A chronic, inflammatory skin condition that primarily affects the face and is characterized by redness and pustules (small, pus-filled pimples) (1).
How common is rosacea?
Globally, about 5% of the adult population is affected by rosacea, predominantly those between ages 45 and 60 (2).
It is more common in people with fair skin (3).
What are the signs and symptoms?
The most common signs and symptoms of rosacea affect the skin, mainly in the center of the face (1):
- Burning or stinging skin
- Dry, scaly skin
- Facial edema (swelling)
- Facial erythema (redness)
- Flushing (sudden reddening of the face)
- Glandular hyperplasia (enlarged sebaceous glands)
- Papules (bumps)
- Patulous follicles (enlarged pores)
- Pustules (pimples)
- Skin thickening or fibrosis (scarring)
- Telangiectasia (small, broken or dilated blood vessels) on the skin
Some people may also experience ocular (eye-related) symptoms (1):
- Blepharitis (swollen eyelids)
- Burning or stinging eyes
- Conjunctivitis (pink eye)
- “Honey crust” (honey-colored buildup at the base of the eyelashes)
- Light sensitivity
- Telangiectasia (small, broken or dilated blood vessels) in the eyes
What causes rosacea?
It is well known that rosacea tends to run in families. A recent study suggests a 46% genetic contribution (4, 5).
A group of genes called the human leukocyte antigen (HLA) complex, which helps the immune system recognize and respond to foreign proteins, may play a role in rosacea (6, 7).
Glutathione S-transferases (GSTs), another group of genes responsible for protecting cells from oxidative stress, may also be involved (6).
Currently, only one SNP (rs763035), has been associated with rosacea, so more research is needed (7).
2. Abnormal immune response
The innate immune system is the body’s first line of defense against infection and injury (8).
In patients with rosacea, this is dysregulated, leading to an abnormal release of inflammatory mediators and anti-microbial peptides (AMPs) in response to triggers (9).
One particular type of AMP known as cathelicidin promotes blood vessel dilation and inflammation, and having high levels is linked with rosacea (10).
3. Vascular changes
It is thought that certain triggers, such as stress or heat, stimulate the release of neurotransmitters and other mediators that cause blood vessels to dilate in patients with rosacea (3).
As a result, blood flow to the face is increased and symptoms like flushing and erythema can occur (11).
There is also some evidence of angiogenesis (the growth of new blood vessels), although more research is needed (12).
4. Skin barrier dysfunction
The skin barrier is responsible for protecting the body from external threats (bacteria, viruses, chemicals, etc.) and preventing excessive water loss (13).
In rosacea, the permeability of this barrier is increased, resulting in dry skin that’s more prone to irritation (14).
Currently, scientists aren’t sure whether this alteration in skin barrier function is a cause of rosacea, or simply a result of the inflammation that occurs (15).
5. Parasitic mites?
Demodex are microscopic parasitic mites that live in or near hair follicles of humans and other mammals (16).
Infestation with Demodex is very common and usually doesn’t cause any symptoms, but it can trigger inflammation if mites penetrate the skin (16, 17).
A recent meta-analysis of case-control studies showed that patients with rosacea were more likely to be infested by Demodex mites and had a significantly higher Demodex density compared to controls (18).
More research is needed to determine whether Demodex mites play a causal role in the development of rosacea (19).
6. H. pylori?
Helicobacter pylori is a common spiral-shaped bacteria that colonizes the lining of the stomach (20).
It is thought that H. pylori might play a role in the development of rosacea by increasing inflammation and oxidative stress (21).
However, a recent meta-analysis found only a weak and statistically insignificant association between rosacea and H. pylori infection (22).
What conditions are linked with rosacea?
Abnormal immune responses play a role in both rosacea and allergies (9).
Studies show that contact allergies to nickel (in jewelry), fragrance, and formaldehyde (in cosmetics) are common in people with rosacea (23, 24, 25, 26, 27).
It is also linked with a higher prevalence of food allergies (4).
2. Autoimmune disease
Rosacea has been linked with several autoimmune disorders, including type 1 diabetes, celiac disease, multiple sclerosis, and rheumatoid arthritis (28).
Experts have suggested this link can probably be explained by shared genetic risk factors between rosacea and autoimmune disease (28).
3. Gastrointestinal disorders
A 2017 study found significant associations between rosacea and gastrointestinal disorders, including Crohn’s disease, ulcerative colitis, small intestinal bacterial overgrowth, and irritable bowel syndrome (29).
In a study submitted as a letter to the editor, patients with rosacea were 13 times more likely to have SIBO compared to controls (30).
It’s unclear exactly why these conditions are linked, but it has been suggested that dysbiosis might play a role in rosacea (29).
4. Metabolic syndrome
A recent meta-analysis found a significant association between rosacea and metabolic syndrome, a group of risk factors that increase the likelihood of developing heart disease and diabetes (31).
These risk factors include hypertension, hyperglycemia, abdominal obesity, high triglycerides, and low HDL (32).
It is thought that systemic inflammation caused by rosacea might be responsible for these effects (31).
5. Anxiety and depression
Rosacea is associated with an increased risk of developing anxiety and depression (33, 34, 35).
Facial redness and flushing are often misinterpreted as signs of alcohol abuse, anger, or embarrassment, so many patients with rosacea prefer to avoid social situations (33).
Stress and anxiety also aggravate rosacea symptoms, which can further increase psychological distress (33).
Several studies have found a significantly higher prevalence of migraine in female (but not male) patients with rosacea (36, 37).
More research is needed to understand this link, but it is known that rosacea and migraine share several pathophysiological mechanisms.
For example, both involve the release of neuropeptides (small proteins released by neurons that act as signaling molecules) and changes in blood flow to the face (36).
How is it diagnosed?
Rosacea is diagnosed when one of the following signs is present (1):
- Fixed redness in a characteristic pattern that may periodically intensify.
- Swelling changes, which can include enlarged pores, skin thickening or fibrosis, enlarged sebaceous glands, and a bulbous appearance of the nose.
In the past, rosacea was further classified based on the following “subtypes” (38, 39):
- Subtype one (erythematotelangiectatic) is characterized by flushing and persistent redness of the face.
- Subtype two (papulopustular) is characterized by persistent redness of the face with papules and pustules.
- Subtype three (phymatous) is characterized by thickening of the skin, primarily around the nose, chin, forehead, eyes, or eyelids.
- Subtype four (ocular) is characterized by eye-related symptoms, such as burning/stinging/itching eyes, sensitivity to light, and swollen eyelids.
However, experts are recommending a transition to a new classification system based on the following phenotypes (1).
- Papules and pustules
- Ocular manifestations
- Burning or stinging
- Dry appearance
What are some common triggers?
1. Sun exposure
One of the most common triggers for flushing and other rosacea symptoms is recent sun exposure (9).
It is thought that ultraviolet (UV) radiation initiates a pro-inflammatory response and promotes blood vessel growth in rosacea (9).
Many patients report an increase in symptoms during very hot or humid weather, which may be caused by blood vessel dilation as the body attempts to regulate body temperature (40).
On the other hand, extremely cold or windy weather may also cause a flare up, possibly due to its drying effect on the skin (40).
Flushing is a common symptom that is often triggered by anxiety and stress in patients with rosacea (41).
Increased alcohol intake is associated with a greater risk for developing rosacea, and many patients report that alcohol seems to trigger flushing and redness (42, 43).
This might be explained by alcohol’s role in promoting inflammation and vasodilation, both of which are thought to be involved in the development or rosacea (42).
5. Cosmetics and skin care products
It is generally recommended that patients avoid any harsh skin care products that might irritate the skin and trigger rosacea symptoms (3).
There aren’t any specific guidelines or studies to suggest which specific products or ingredients need to be avoided, but fragrances and formaldehyde may worsen symptoms (24).
During exercise, blood vessels dilate to increase blood flow to muscles throughout the body (44).
This vasodilation is thought to play a role in rosacea, and many patients report that intense exercise triggers flushing (41).
Many patients report that certain foods (especially those that cause a warming sensation), such as the following, act as triggers (45):
- Capsaicin (the active component of chili peppers) (46)
- Cinnamaldehyde (an active component of cinnamon, also found in tomatoes, citrus, and chocolate) (9, 47)
- Hot foods and beverages (such as coffee, tea)
More research is needed to determine if any other foods might worsen rosacea symptoms.
How is rosacea typically treated?
1. Avoidance of triggers
Doctors may advise patients with rosacea to keep a diary of lifestyle and environmental factors in order to identify triggers (48).
Avoiding these triggers is the simplest way to reduce symptoms and prevent flare-ups.
2. Skin care
In order to protect the skin and prevent irritation, sunscreen providing at least 30 SPF is recommended (19, 48).
Mineral-based sunscreens made with zinc oxide or titanium dioxide are preferred because they are less likely to trigger symptoms (48).
Gentle skin care products (cleanser, moisturizer, etc.) are also recommended, but clinical studies aren’t available to determine which ones are best for rosacea (48).
3. Topical treatments
Medicated facial creams and gels are often prescribed to help calm inflammation, kill bacteria and parasites, and reduce redness (48).
Some of these include azelaic acid, ivermectin, metronidazole, brimonidine, oxymetazoline, and sodium sulfacetamide (45, 48).
4. Oral medication
Antibiotics (such as tetracycline, doxycycline, metronidazole, etc.) are sometimes recommended to treat papules and pustules (48).
Isotretinoin (Accutane) can also be prescribed off-label if other medications fail to resolve symptoms (48).
More recently, beta blockers (propranolol, carvedilol, etc.) have been suggested to reduce redness and flushing (40, 49).
5. Laser and light therapy
Therapies involving light and lasers are used to treat telangiectasias (visible, damaged blood vessels) and facial redness (45).
Pulse-dye lasers (PDL) emit short bursts of light (at a wavelength of 585 nm) which are converted to heat that destroys damaged blood vessels without harming the surrounding tissue (50, 51).
Intense pulsed light (IPL) is different from laser therapy because it uses several wavelengths of light to reduce redness and even out skin tone (52).
Are elimination diets helpful for rosacea?
Inflammation plays a role in the development of rosacea and food sensitivities can contribute to this (9, 10, 23, 53).
In one case study, a patient with rosacea who followed a diet that eliminated dairy, reduced high glycemic foods and red meat, and was mostly plant-based was able to clear her skin within 2 months (54).
However, much more research is needed.
Which nutrients might play a role in rosacea?
An older (2006) study found that zinc sulfate supplementation (300 mg/day) significantly improved rosacea severity after 3 months (55).
The mechanism is unclear, but scientists have suggested zinc might protect against rosacea by reducing inflammation, Demodex mites, and H. pylori (55).
However, a 2012 trial showed no differences in rosacea symptoms between participants with severe facial rosacea and healthy controls after zinc sulfate supplementation (440 mg/day for 3 months) (56).
Additional studies are needed.
2. Omega-3 fatty acids?
Omega-3 fatty acids may improve ocular (eye-related) rosacea symptoms, such as dry eye by decreasing inflammation and improving the function of meibomian glands, which secrete oil to coat the surface of the eye and prevent tears from evaporating (57).
A 2016 trial found that participants with rosacea and dry eye symptoms who received omega-3 supplements (360 mg EPA + 240 mg DHA) twice daily for 6 months showed significant improvement in dry eye symptoms (57).
More research is needed to determine whether omega-3s might be beneficial for reducing other symptoms of rosacea.
3. Vitamin D?
Vitamin D is thought to play a role in rosacea enhancing immunity and modulating the production of antimicrobial peptides and cytokines (58).
A small study showed significantly higher vitamin D levels in participants with rosacea compared to the control group (58).
More research is needed to confirm this link, but the authors suggested that increases in vitamin D (caused by sun exposure) trigger the release of cathelicidin peptides (a type of antimicrobial peptide) and inflammation leading to rosacea symptoms in susceptible individuals (58).
Are any other supplements beneficial?
There is some evidence that probiotics (such as Lactobacillus paracasei) reduce skin inflammation and improve skin barrier function (9, 59).
A 2016 case study showed a decrease in symptoms in a patient with rosacea who was treated with a combination of antibiotics and probiotics (Bifidobacterium breve and Lactobacillus salivarius) for 8 weeks (60).
However, there haven’t been any clinical trials.
Are there any other alternative treatments?
Acupuncture might play a role in rosacea treatment because it can reduce neurogenic inflammation (61).
There have been reports of reduced rosacea symptoms in patients who received facial acupuncture several times per week (61).
However, no trials have been conducted as of yet.
2. Topical honey?
Kanuka honey is a type of honey made by bees that pollinate the kanuka tree in New Zealand (62).
Evidence from in vitro studies suggests it has strong anti-inflammatory and anti-bacterial properties (62, 63).
A 2015 trial found that patients with rosacea who were treated topically with a combination of medical-grade kanuka honey (90%) and glycerin (10%) showed significant improvements in symptoms after 8 weeks (64).
Erica is a registered dietitian nutritionist and lover of science and learning. She has a never-ending passion for education, and gladly spends her time writing & growing this blog! When she’s not at the computer, she can be found in the kitchen with her family, rocking out to good music and cooking up a storm.