Some skin conditions can be tricky to diagnose because they share certain symptoms. Seborrheic dermatitis and atopic dermatitis, for example, are two distinct types of eczema, both of which can cause dry and itchy skin.

Often, people think specifically of atopic dermatitis when talking about eczema. “All of the seb derm remedies I’ve tried — ketoconazole, zinc, coal tar shampoos — have not worked or have left me with an irritated scalp. Might it be eczema? Is there any difference?” asked a member of MySebDermTeam.

Despite their similarities, seborrheic dermatitis and atopic dermatitis have some key differences, which can help a doctor tell them apart. Here’s what you need to know about the similarities and differences between seborrheic and atopic dermatitis.

Seborrheic Dermatitis vs. Atopic Dermatitis: An Overview

As noted, seborrheic dermatitis and atopic dermatitis are both types of eczematous dermatitis. The word “dermatitis” refers to skin inflammation. “Seborrheic” refers to sebum, a type of oil produced from the skin’s sebaceous glands. “Atopic” refers to a tendency for allergic disease, which can result in sensitivity and allergic reactions.

Generally speaking, eczema weakens the skin barrier, also known as the stratum corneum. This outermost layer of the skin 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

Around 11 percent of the population has seborrheic dermatitis, which primarily affects infants and adults between the ages of 30 and 60. The condition is characterized by greasy, white, flaky patches on the skin and scalp.

Atopic dermatitis — also called atopic eczema — is a common form of eczema that affects around 15 percent to 20 percent of children and 1 percent to 3 percent of adults globally. People usually develop the condition by age 5, but it can show up at any age. The condition is associated with dry skin and itchy, painful rashes that can develop anywhere on the body.

Symptoms

Seborrheic and atopic dermatitis present differently, although they have some overlap, including rash and itchiness.

Symptoms of Seborrheic Dermatitis

Symptoms of seborrheic dermatitis can appear anywhere except the palms of your hands and soles of your feet. In babies, it most commonly develops on the scalp, which is why it’s referred to as cradle cap. It 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. It can also be found in skin folds, such as the navel, groin, and under the breasts.

Other symptoms of seborrheic dermatitis include:

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

Symptoms of Atopic Dermatitis

Symptoms of atopic dermatitis can develop anywhere on the body. Common symptoms include:

• Dry, cracked skin
• Scaly patches of skin
• Itchiness
• Discolored rash (red, brown, purple, or gray, depending on skin tone)
• Small bumps filled with fluid
• Oozing and crusting
• Thickened skin

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Causes

Scientists are still trying to pinpoint the exact causes of these conditions. They believe both environmental and genetic factors play a role. The way the skin biome — the ecosystem of various microorganisms that live on our skin — interacts with the immune system may also contribute to the development of symptoms. Importantly, neither atopic dermatitis nor seborrheic dermatitis is contagious.

Causes of Seborrheic Dermatitis

Scientists aren’t entirely sure what causes seborrheic dermatitis. They’ve connected the condition to Malassezia, a type of yeast that is present on most people’s skin and is generally harmless. In some people, however, the yeast activates the immune system and causes skin inflammation.

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 the oil. It’s possible that Malassezia feeds on the sebum, which contributes to its growth.

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 having seborrheic dermatitis.

Causes of Atopic Dermatitis

In atopic dermatitis, scientists believe a combination of genetic and environmental factors plays a role. For some people, the condition comes from a variation in a gene resulting in weakened skin barrier function. The skin barrier is then less able to protect against bacteria, allergens, irritants, and environmental factors, like cigarette smoke. According to the NHS, a person is more likely to develop atopic dermatitis if they have at least one first-degree relative (a parent or sibling) with the condition. Part of the immune system becomes overactive, leading to inflammation of the skin.

Atopic dermatitis has also been linked to a type of bacteria called Staphylococcus aureus. Many people have this bacteria as part of the skin microbiome, and it causes no harm. But in some people, it can become harmful, possibly leading to atopic dermatitis and other skin conditions. Some research has found that 90 percent of people with atopic dermatitis have S. aureus on their skin lesions.

Diagnosis

Initially, a dermatologist will take a similar approach to diagnose atopic dermatitis and seborrheic dermatitis. Diagnosis usually starts with a health care provider examining your skin, assessing your symptoms, and reviewing your medical history.

In some cases, if you show signs of other skin conditions, a doctor may perform a biopsy. This procedure entails removing a small piece of affected skin to be viewed under a microscope, so the doctor can look for inflammation patterns that lead to a diagnosis.

For atopic dermatitis, a doctor may also perform a blood test or a patch test to rule out other conditions or allergies. The patch test involves applying small amounts of potential allergens to your skin to see if there are any reactions.

Treatments

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

Both conditions, when mild, may be manageable using over-the-counter (OTC) skin care products. Skin care experts also recommend some lifestyle changes to improve symptoms for both conditions, including:

• Managing stress through techniques such as light exercise, journaling, or meditation
• Getting quality sleep
• Eating a healthy diet — Some research suggests an anti-inflammatory diet may help with both conditions.

For both atopic and seborrheic dermatitis, avoiding triggers — such as harsh detergents and soaps and cold, dry air — can also help.

For more severe cases, a doctor may prescribe topical or systemic corticosteroids, human-made synthetic hormones that suppress immune system responses. These medications can help reduce inflammation that causes uncomfortable symptoms.

The conditions share some potential treatments, but there are also differences.

Seborrheic Dermatitis Treatments

Treatments for seborrheic dermatitis vary, depending on the age of the person with the condition and its severity.

For infants with seborrheic dermatitis, shampooing the scalp daily and using a soft brush to loosen crust and scales may help. Applying mineral oil or petroleum jelly before bath time can help remove heavier scaling. In more severe cases, a pediatrician may prescribe a low-dose steroid cream like hydrocortisone or an 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.

For seborrheic dermatitis on the scalp, OTC dandruff shampoos containing ingredients such as coal tar, selenium sulfide, zinc pyrithione, or salicylic acid may help. Your doctor also may prescribe prescription shampoos with antifungal agents to help get rid of dandruff and keep your scalp clear.

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

• Topical corticosteroids
• Topical calcineurin inhibitors
• Topical antifungals
• Oral antifungal medication
• Phototherapy

Atopic Dermatitis Treatments

For atopic dermatitis, your doctor may first recommend a regimen of applying moisturizers or ointments. If that doesn’t work, they may prescribe a medicated cream to help reduce inflammation and itchiness and repair skin.

It can also help to identify and avoid triggers for atopic dermatitis, which vary from person to person. Triggers are environmental factors that may aggravate the skin condition and can include:

• Wool
• Heat and sweat
• Dust and dander
• Mold
• Pollen
• Tobacco smoke
• Certain fragrances

Prescription treatments for atopic dermatitis — some of which overlap with treatments for seborrheic dermatitis — include:

• Topical corticosteroids
• Oral steroids
• Antibiotics
• Cool, wet dressings
• Injectable biologics
• Oral immunosuppressants
• Oral Janus kinase (JAK) inhibitors

Your Doctor Will Know Best

Seborrheic dermatitis and atopic dermatitis are just two of many skin conditions that may share symptoms. Although 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.

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.