A woman shaking out her blond and brown hair.

Psoriasis vs. Seborrheic Dermatitis: Differences Explained

A woman shaking out her blond and brown hair.

Many people suffer from issues related to a flaky, itchy scalp, but did you know that multiple conditions can cause these problems? It’s essential to understand the various conditions that could be at play and which one you’re most likely struggling with to figure out the best treatment method. 

Below, our dedicated skincare experts from Soteri Skin will explore two of the most common conditions that can lead to an itchy, irritated scalp; psoriasis and seborrheic dermatitis. Please continue to learn more, and consider exploring our selection of other great skincare resources available on our website. 

Related: The Right pH Level is Everything

The Symptoms of Psoriasis

Psoriasis is a common type of long-term (chronic) skin disease that typically causes a rash on the scalp, elbows, knees, hands, and feet in the form of itchy, scaly, raised patches. Aside from these patches, the disease can also lead to the development of bleeding, cracking skin, and white-silver scales that produce a painful or burning sensation. It can also trigger flaking that generally resembles dandruff, and the rash typically appears cyclically every few weeks or months before subsiding. 


While medical professionals don’t know the exact cause of psoriasis, researchers believe that genetics plays a critical role in the condition’s development. Experts also agree that specific environmental triggers can make the body send incorrect signals to the immune system, causing skin cells to grow more rapidly than needed. Some common triggers of psoriasis flare-ups include;

  • Skin injury
  • Stress
  • Certain medications
  • Infections (including tonsillitis, strep throat, and bronchitis)

The Types of Psoriasis

person with psoriasis on the arm and hand


There are five general types of psoriasis that people typically experience, each of which can produce a slightly different impact on the skin. These psoriasis types include;

Guttate Psoriasis

This type of psoriasis takes the form of small, dotted lesions and impacts around 10% of all psoriasis cases.

Inverse Psoriasis

Inverse psoriasis causes smooth, red, and shiny lesions to develop in skin folds, like the armpits, backs of the knees, and groin. It can also make specific folds more prone to fungal or yeast infections. 

Plaque Psoriasis

This particular type of psoriasis is the most common and causes a series of raised, red patches with an itchy and painful white buildup of dead skin cells.

Pustular Psoriasis

Pustular psoriasis causes white pus blisters on the hands and feet surrounded by red areas of inflamed skin.

Erythrodermic Psoriasis

The most problematic and least common type of psoriasis is erythrodermic psoriasis. It causes a painful, fiery redness to spread throughout the body. The condition can cause severe itching and cause the skin to peel off the body. Only around 3% of people with psoriasis have this particular variant. 

Related: The Basics: Skin 101

The Symptoms of Seborrheic Dermatitis

Seborrheic dermatitis- also called dandruff or cradle cap in babies- is a common skin condition that mainly affects the scalp, causing red skin with scaly patches and stubborn dandruff. It can also negatively impact oily areas of the body, including the face and chest. The condition can often go away without treatment in some people, though others may need repeated treatments before symptoms go away. Even with treatment, however, the symptoms may eventually return.


Much like with psoriasis, medical professionals don’t fully understand the exact cause of seborrheic dermatitis, though genetic factors are thought to be a major contributor. Beyond that, some other potential triggers for flare-ups include;

  • Hormonal changes
  • Intense stress
  • Illnesses
  • Exposure to certain chemicals
  • Certain harsh soaps, solvents, and detergents
  • Dry weather
  • The presence of certain microorganisms on the skin

Soteri Skin products can help you achieve the perfect skin pH!

Determining the Difference Between Them

When determining the difference between psoriasis and seborrheic dermatitis, doctors will typically look at the symptoms involved and how the condition presents itself within a patient. Because both conditions have a similar range of symptoms- including scaly patches of skin, itching, and flaking- doctors typically look at the kind of scales that appear on the skin.

For example, psoriasis often causes red or pink skin discoloration with silvery-white scales in those with lighter skin tones and reddish-brown or purple patches with white or grayish scales in darker skin tones. In contrast, seborrheic dermatitis scales usually appear more pinkish-yellow with yellow flakes in those with lighter skin tones and have a more harsh red appearance with flaking in those with darker skin tones. Seborrheic dermatitis scales are also usually thinner and more greasy in appearance. 

How to Treat Psoriasis

A woman coming out of the water with wet hair.


Several treatments are available for psoriasis depending on the type that people are struggling with, and each type requires slightly different interventions. When it comes to scalp psoriasis, for example, treatment is often complicated and time-consuming and requires a lot of coal tar and salicylic acid products. There are also several medicated shampoos people can get over the counter to treat psoriasis scalp lesions and reduce itching.

Soteri Skin scalp serum utilizes our innovative and patented pH/LOCK™ technology, is invisible, doesn't make hair greasy, and offers targeted pH-correction.

Generally, it’s best to bathe the scalp in warm water before applying ointments, creams, and lotions. This will make the plaques softer and can help remove them from the scalp. People may need to rely on intense topical treatments in more severe cases.

How to Treat Seborrheic Dermatitis

Seborrheic dermatitis treatment usually depends on the severity of the condition and how people respond to the various medications doctors can prescribe to treat the issue. Mild cases can generally be treated with a topical antifungal cream or medicated shampoos. However, those with more severe cases may also need additional treatments with corticosteroids to reduce inflammation.

Related: 5 Tips for Managing Itchy, Flaky Skin from Dermatologist Xiaoxiao Li, MD

When to See a Doctor

Anyone dealing with either of these conditions should consult their doctor for medical advice, especially if their rashes, pustules, or lesions don’t respond to over-the-counter remedies over an extended period. This can indicate a more chronic condition, and patients may benefit from having skin samples removed and tested for more information.

Final Thoughts

Our dedicated skincare experts from Soteri Skin hope that the above information has covered the basics of everything you want to know about psoriasis, seborrheic dermatitis, and the critical differences between the two conditions. Please consider exploring our shop to learn more about our specially formulated products and how they can help you achieve happier, healthier, and clearer skin. 

Ready to revolutionize your skincare routine? Soteri Skin is here to help!