Both seborrheic dermatitis (SD) and rosacea are skin disorders that can cause inflammation and scaling on the face. However, they likely have different causes.
Scientists believe SD may occur due to the body’s reaction to a type of yeast that grows on the skin. This yeast tends to grow in areas that produce oil, also known as sebum, such as around the nose, the eyelids, or on the scalp.
The causes of rosacea are complex, with multiple factors such as genetics, infections, and the immune system potentially playing a role. The condition can also appear in similar areas to SD, and some people have both conditions.
This article will review the differences between rosacea and SD, including how their symptoms, causes, and treatment options compare.
Rosacea and SD are common skin conditions that cause inflammation. They have various similarities and differences.
Similarities
Both conditions can occur in various places but often affect the face. They both cause a person to develop inflamed patches of skin. These patches may look pink or red on light skin tones and light or dark brown on dark skin tones.
Rosacea and SD also both cause itchiness and changes in skin texture, such as roughness or flaking.
Neither condition is contagious. However, they are both chronic, meaning they persist over time.
Differences
Despite these similarities, the presentation of rosacea and SD differs.
For example, one of the main symptoms of rosacea is redness or discoloration with visible blood vessels. The skin may feel dry and sensitive and sting or burn more intensely.
While SD can look red on certain skin tones, it can also appear waxy and flaky, usually with mild itchiness.
SD and rosacea can both cause inflammation and scaling on the face. However, the conditions differ in their presentation.
Rosacea symptoms
The symptoms a person with rosacea experiences will depend on the subtype. These subtypes include:
- Papulopustular rosacea: This subtype causes flushing, redness or discoloration, and visible blood vessels. It affects the center of the face, which includes the cheeks, nose, and forehead.
- Erythematotelangiectatic rosacea: This subtype resembles acne, with breakouts or flare-ups that come and go.
- Phymatous rosacea: This rare subtype causes bumpy, thickening skin, often on the nose.
- Ocular rosacea: This subtype affects the eyes and may cause them to appear red or bloodshot. It may also cause a gritty sensation in the eyes, watering or tearing, cysts on the eyelids, or sensitivity to light.
Although the symptoms of rosacea can vary quite widely, any of these subtypes may make the skin:
- itch, sting, or burn, sometimes intensely
- feel swollen, tender, or raised
- develop hard lumps or a rough texture
- very sensitive
SD symptoms
In contrast, SD does not have as many variations in its appearance as rosacea does.
It can appear anywhere on the body but generally occurs in places that generate oil, such as the:
- sides of the nose
- forehead and eyebrows
- eyelids
- chin
- scalp
- ear area
- chest and back
Patches of SD may:
- look flaky or scaly
- have a greasy or waxy appearance
- appear as raised plaques
- be itchy, although the itching tends to be mild
- cause dandruff, if a patch is on the scalp
The underlying causes of rosacea and SD are unclear, as scientists are still learning about them. However, several factors may contribute to both.
Rosacea causes
It is unclear what causes rosacea, but some people may be more likely to have the condition than others. This includes people with:
- a family history of rosacea
- Celtic or Scandinavian heritage
- light skin and blue eyes or blonde hair
This could suggest a genetic link. However, it is important to note that people of any background or skin tone can develop rosacea.
Other potential causal factors include:
- Helicobacter pylori (H. pylori) infection: People with rosacea commonly have H. pylori, a bacterial infection. However, many people have H. pylori and experience no symptoms.
- Mites: Tiny mites known as Demodex folliculorum live on human skin. Many people with rosacea have large numbers of these mites on their skin. However, this can also be true for people without rosacea.
- Cathelicidin: The lesions typical of rosacea
may occur due to a protein called cathelicidin that protects the skin from infections. In some cases, this substance can also cause inflammation. The way the body processes this protein may play a role in whether a person develops rosacea. - Immune system reactions: Rosacea may occur when the immune system overreacts to a bacterium known as Bacillus oleronius. However, more research is necessary to understand the potential involvement of the immune system in the onset of this condition.
SD causes
Dermatologists believe SD may occur due to a type of yeast called Malessezia that lives on the skin of all humans.
It is unclear if the yeast grows too much in certain people or if some develop a reaction to the yeast that is otherwise not causing problems. Antifungal treatments often improve the symptoms.
However, SD is not an infection and does not occur because of a lack of cleanliness. The amount of oil the skin produces or the activity of a person’s immune system may explain why some develop SD, and others do not.
People with conditions that impair the immune system, such as HIV or cancer, are more likely to have SD. Neurological disorders such as Parkinson’s disease also have links to SD.
Rosacea and SD are not related.
However, it is not uncommon for these two skin disorders to occur at the same time. A survey by the National Rosacea Society found that 25% of people with rosacea also had SD on their face or scalp.
This may be because both conditions cause skin inflammation and lesions, which may lead to skin infections and further inflammation. More research is necessary to understand why rosacea and SD co-occur.
Doctors mainly diagnose both skin disorders based on symptoms. However, because of their similarities, it can sometimes be challenging to tell them apart.
To identify a skin condition, doctors
While people with rosacea typically experience a scattered distribution of white scales, people with SD typically present yellow scales that form in patches.
A
Treating rosacea involves avoiding known triggers and protecting the skin.
Doctors may recommend using appropriate clothing and sunscreen to protect the skin from the sun and the cold weather. Using skin care products that are gentle and suitable for rosacea is also important.
Some medications and laser treatments may help reduce the signs of rosacea, such as skin redness or discoloration. However, a person’s everyday habits play a significant role in reducing the risk of rosacea flare-ups, even with treatment.
Treatments for SD may include:
- antifungal medications
- topical steroids
- antidandruff preparations for the scalp
In some cases, doctors may prescribe short-term medications to reduce inflammation or soften and remove crusts on the skin.
Rosacea and seborrheic dermatitis (SD) are skin disorders with several common symptoms, such as skin inflammation, flaking, and changes in skin color. However, these two conditions are distinct.
Where rosacea often causes redness or discoloration, visible blood vessels, or acne-like breakouts, SD’s most characteristic symptoms are patches of scaly skin that occur in areas where the skin produces oil.
Antifungal and anti-inflammatory treatments may help with SD. Dermatologists advise people with rosacea to avoid triggers and protect their skin from irritants, such as UV light or skin products. Other treatments, such as medications or laser therapy, may also help reduce the appearance of rosacea symptoms.