Many skin conditions share similar symptoms, which can make them difficult to distinguish and diagnose. Two of these overlapping conditions are seborrheic dermatitis and rosacea. Both of these chronic (ongoing) skin disorders can cause discoloration (which can appear red or dusky brown, depending on skin color), burning or itching sensations, scaling, and oiliness.

Despite the similarities between seborrheic dermatitis and rosacea, these conditions have many key differences, which can help a doctor tell them apart. Here is what you need to know about the similarities and differences between seborrheic dermatitis and rosacea.

1. Seborrheic Dermatitis Is More Common Than Rosacea

Seborrheic dermatitis is a form of eczema that causes the skin’s natural protective barrier to not work properly. The skin barrier is the outermost layer of the skin that acts as a protective barrier between the body and the outside environment. Its functions include:

• Regulating temperature
• Retaining moisture
• Preventing infection and inflammation
• Keeping skin looking and feeling healthy

Seborrheic dermatitis affects around 11 percent of the population. It primarily affects infants and adults between the ages of 30 and 60. The condition is characterized by greasy, white, flaky patches on the face, scalp, and chest.

Rosacea affects about 5.5 percent of the global population. It is a common skin condition that affects the face and forehead. There are four subtypes of rosacea, and it’s possible to have more than one type at the same time.

Symptoms of rosacea can include blushing or flushing, acnelike breakouts, visible blood vessels, and eye-related symptoms including burning and blurred vision. Discoloration from rosacea on the face can become permanent over time.

Anyone can develop rosacea, although the condition is most common among people ages 30 to 50 and individuals of Celtic or Scandinavian ancestry. It’s more prevalent among women, although it tends to be more severe in men, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Rosacea may be underdiagnosed in people with darker skin, however.

2. Both Conditions Can Cause Itchy and Oily Skin, but Only Rosacea Causes Spider Veins

Although seborrheic dermatitis and rosacea appear differently, they have some overlapping symptoms. For example, these include discoloration, oily skin, burning or itchiness, and scaling on affected areas.

Symptoms of Seborrheic Dermatitis

Symptoms of seborrheic dermatitis usually appear on the sides of the nose and around the eyebrows on the face and on the scalp and ears. In babies, the condition most commonly develops on the scalp, which is why it’s often called cradle cap. Seborrheic dermatitis can also affect an infant’s skin folds and, less commonly, diaper area.

In adults, seborrheic dermatitis tends to develop on oily areas of the body, including the scalp, forehead, nose, eyebrows, ears, eyelids, mouth, back of the head and neck, and chest.

Other symptoms of seborrheic dermatitis include:

• Dry, flaking skin
• Greasy patches of skin with discolored scales (white or yellow)
• Crusting
• Rash on various parts of the body
• Burning or itching sensations, particularly on the scalp

Symptoms of Rosacea

Rosacea generally starts with unusually high blushing or flushing. Over time, the redness causes permanent dilation (widening) of the blood vessels on the face.

Other symptoms vary depending on the type or types of rosacea a person has:

• Erythematotelangiectatic rosacea — Characterized by redness, flushing, swollen skin, stinging or burning sensations, and visible blood vessels (spider veins)
• Papulopustular rosacea — Symptoms include discoloration, spider veins, plaques (raised patches of skin), oily skin, pustules (swollen bumps and pus-filled blemishes), and acnelike lesions
• Phymatous rosacea — A rare subtype of rosacea that can cause the skin to thicken — most often in the nose — and develop a bumpy texture leading to disfigurement; oily skin and spider veins are also common
• Ocular rosacea — Affects the eyes, causing redness, irritation, swollen eyelids, light sensitivity, and impaired vision

3. Yeast May Contribute to Seborrheic Dermatitis, and Bacteria May Influence Rosacea

Scientists are still trying to determine the exact causes of these skin diseases. They believe environmental and genetic factors both play a role. The way the skin biome — the ecosystem of bacteria, fungi, and viruses that live on our skin — interacts with the immune system may also contribute. Importantly, neither seborrheic dermatitis nor rosacea is contagious.

Causes of Seborrheic Dermatitis

Scientists aren’t entirely sure what causes seborrheic dermatitis, but there are a few conditions associated with it.

Malassezia

A type of yeast called Malassezia that’s found on most people’s skin and is generally harmless has been connected to seborrheic dermatitis. In some people, however, their immune system reacts to the yeast and causes skin issues.

Excess Sebum

Scientists have also linked seborrheic dermatitis to an excess of sebum, an oil naturally produced by the skin’s sebaceous glands. The American Academy of Dermatology Association notes that seborrheic dermatitis tends to develop in people when their bodies are producing more sebum and in parts of the body that contain higher amounts of oil. It’s possible that Malassezia feeds on the sebum, which contributes to its growth.

Inherited Gene Changes

Researchers believe that some inherited gene changes may contribute to the development of seborrheic dermatitis. Having a family member with dermatitis or a general skin inflammation disorder increases your chances of developing seborrheic dermatitis.

Causes of Rosacea

As for rosacea, scientists believe a combination of genetic and environmental factors play a role. There are several potential causes of rosacea.

Genetics

Researchers have determined that people with rosacea are four times more likely to have a family history of the condition than people without it. It’s unclear, though, how much genetics factor in versus nongenetic factors that family members might share, such as exposure to certain environmental risk factors.

Immune System Reaction

Most people with papulopustular rosacea (the subtype with acnelike symptoms) experience an immune system overreaction to a type of bacteria called Bacillus oleronius, which comes from a Demodex mite. These bacteria are a natural part of the human microbiome that tend to live in the face and eyelids. It’s unclear why the bacteria cause rosacea in some people but not others.

Infection

A bacteria called Helicobacter pylori (H. pylori) causes gastrointestinal issues such as gastric cancer and ulcers. H. pylori is common among people with rosacea. Research has suggested that getting rid of the H. pylori infection with antibiotics may improve rosacea symptoms. However, not everyone with H. pylori develops rosacea.

Excess Cathelicidin

Researchers have found high levels of cathelicidin antimicrobial peptides — proteins that normally protect from skin infections — on the facial skin of people living with rosacea. It is not clear what causes this overproduction.

4. Medical Tests Sometimes Help Diagnose Either Condition, but the Diagnosis Is Usually Based on Symptoms

There are currently no blood tests that can definitively determine if you have rosacea or seborrheic dermatitis.

For both conditions, a dermatologist will start by examining your skin, assessing your symptoms, asking about triggers, and reviewing your medical history. If you have symptoms that affect your eyes, your doctor may refer you to an ophthalmologist (eye specialist).

Sometimes, a doctor may not be able to diagnose your condition only through a physical examination. In those instances, they may order a lab test to rule out other potential causes. These may include a skin biopsy, which entails removing a small piece of affected skin to view under a microscope.

5. Stress Can Trigger Flare-Ups for Both Seborrheic Dermatitis and Rosacea

For both conditions, avoiding triggers can help prevent flare-ups. The conditions have some triggers in common. Stress can be a major trigger, which is why finding ways to manage stress can be especially helpful for preventing and managing flares.

Other seborrheic dermatitis triggers include:

• Cold, dry climate
• Seasonal changes
• Oily skin
• Harsh soaps, chemicals, solvents, and detergents
• Alcohol-based lotions

Common rosacea triggers include:

• Hot drinks
• Spicy foods
• Alcoholic beverages
• Extreme temperatures
• Sun or wind
• Exercise
• Drugs that dilate blood vessels, including some blood pressure medications
• Some cosmetic, skin, or hair care products

6. Neither Condition Is Curable, but Both Are Treatable and Manageable

There are currently no cures for either seborrheic dermatitis or rosacea. However, once you’ve been diagnosed, a dermatologist can work with you to devise a treatment plan to reduce flare-ups and ease symptoms.

Lifestyle Changes

Skin care experts recommend lifestyle changes to improve symptoms for both conditions. You can try to:

• Manage stress through light exercise, journaling, or meditation.
• Get quality sleep.
• Eat a healthy diet. Some research suggests an anti-inflammatory diet may help with both conditions.

Seborrheic Dermatitis Treatments

Treatments for seborrheic dermatitis vary depending on your age and the severity of your symptoms.

For infants, try washing the baby’s scalp with shampoo every day and using a soft brush to loosen the crust and scales. Applying mineral oil or petroleum jelly before bath time can help with heavier scaling. In more severe cases, a pediatrician may prescribe low-dose steroid cream like hydrocortisone or antifungal shampoo containing ketoconazole (Nizoral).

For adults, gentle skin care can help keep milder symptoms of seborrheic dermatitis under control. This may include washing regularly with warm water, using a gentle cleanser, and applying moisturizer.

If you have seborrheic dermatitis on the scalp, over-the-counter dandruff shampoos containing ingredients such as coal tar, zinc pyrithione, selenium sulfide, or salicylic acid may help. Your doctor might suggest using prescription shampoos with antifungal agents to help reduce dandruff and keep your scalp clear.

In more severe cases, a doctor may prescribe treatments such as:

• Topical (placed on the surface of your skin) corticosteroids
• Topical calcineurin inhibitors
• Topical antifungals
• Oral antifungal medication
• Phototherapy

Treatments for Rosacea

Practicing good skin care and using prescription drugs can help keep rosacea symptoms under control.

Skin care includes using sun protection. Stay out of direct sunlight, apply broad-spectrum sunscreen (sun protection factor of 30 or higher), and protect your skin and eyes with a hat, sunglasses, and protective clothing.

Wash with mild soaps and treat your skin gently to help reduce flares.

Prescription treatments for rosacea include:

• Topical drugs that reduce flushing
• Oral antibiotics
• Topical and oral drugs for acne
• Laser therapy

Your Doctor Knows Best

Seborrheic dermatitis and rosacea are just two of numerous different skin conditions, many of which share symptoms. While the above information may provide you with some ideas as to what condition you may have, your doctor is best equipped to diagnose you and help devise the best possible treatment plan for your needs.

Find Your Team

MySebDermTeam is the social network for people with seborrheic dermatitis and their loved ones. MySebDermTeam members come together to ask questions, give advice, and share their stories with others who understand.

Have you been diagnosed with seborrheic dermatitis? What advice do you have for others living with the condition? Share your tips and experiences in a comment below or on your Activities page.