Scalp Psoriasis vs. Dandruff

Dandruff is a common condition involving skin flakes, pruritus (itchiness), and a mild redness of the scalp. Inflammation is not a symptom of dandruff.

Psoriasis, however, is a chronic (long-term) inflammatory disease. Psoriasis can also cause dry, dandruff-like flakes, but it is a much more severe condition.

It’s important to note that although dandruff is a disease and not a symptom, dandruff-like flakes are commonly seen in scalp psoriasis and some other types of scalp conditions. The difference is where the skin breakout occurs, as well as other symptoms—such as plaques and inflammation that occur in psoriasis but not in dandruff.

This article takes a closer look at scalp psoriasis vs. dandruff.

What Is Dandruff?

Dandruff is a very common scalp condition, affecting 50 million people in the United States and nearly half of adults worldwide.

Dandruff is restricted to the scalp area, with itching and flaking without inflammation.

What Is Psoriasis?

Psoriasis is a long-term autoimmune disorder that can affect the scalp and other areas of the body. An autoimmune disorder is one in which the body’s immune system attacks itself.

In psoriasis, the immune system attacks healthy skin cells, causing them to have a much quicker life cycle than normal. This leaves grayish-silvery hardened skin behind, called plaques. Psoriasis cannot be cured and involves periods of flare-ups and remissions.

Studies have shown that approximately half of the cases of psoriasis involve the scalp.

Symptoms

Dandruff

A common sign of dandruff that is often recognized as an initial indication of the condition is noticeable white skin flakes on the hair or shoulders, along with an itchy scalp.

Symptoms of dandruff may include:

• Mild redness of the affected area of the scalp
• Oily scalp
• Itchy skin on the head
• Whitish to yellowish flakes on the scalp
• Dry, flaky skin that worsens in a cold, dry climate
• Scaly, crusty scalp on an infant (called cradle cap)
• Skin infection from excessive scratching

Scalp Psoriasis

Scalp psoriasis may manifest with symptoms such as:

• Small red bumps that increase in size and form scales
• Lesions and dandruff-like flakes on the scalp
• Thick red or white plaques, covered in silvery-colored scales
• Itching that often results in tearing the scales off by scratching
• Extensive hair loss (in severe scalp psoriasis)

Causes

Dandruff

The exact cause of dandruff is not well known, but many experts believe it’s caused by an excess of sebum (oil on the scalp) along with an overgrowth of a type of fungus called Malassezia yeast.

Hormones may also play a role in the development of dandruff; this theory arises because of the prevalence of dandruff in certain life stages when hormone levels are known to be high, such as during infancy (when cradle cap is common) and adolescence, when dandruff often occurs. Factors that influence the development of dandruff flakes include:

• Cold, dry climate (which dries the scalp)
• The use of harsh hair and cosmetic products
• Shampooing the hair too often or not often enough
• A family history of dandruff (dandruff is known to run in families)

Scalp Psoriasis

Most people diagnosed with psoriasis have light skin, but psoriasis can occur in any race. Research studies show that 3.6% of Whites, nearly 2% of Blacks, and 1.6% of Hispanics have psoriasis.

Psoriasis tends to run in families, but some cases of psoriasis are not considered genetic. Having a grandparent, parent, brother, or sister with psoriasis increases the risk of getting it. While researchers are certain that psoriasis isn’t contagious, they are not sure exactly what the underlying cause is.

They do know some things about factors that play a role in its development, such as:

• The immune system’s white blood cells attack the body’s skin cells.
• The immune system attack causes the body to make new skin cells too frequently.
• The excess dead cells that are shed at the end of each cell's life cycle form the visible symptoms seen in psoriasis (such as plaques).

Treatment

Dandruff

The treatment of dandruff usually depends on the severity of the condition. For example:

• Mild dandruff can be treated at home by using a gentle shampoo without any harsh chemicals or ingredients that dry out the scalp.
• Moderate dandruff is usually treated with over-the-counter dandruff shampoos, such as those with selenium sulfide, tar, or zinc pyrithione. These shampoos help promote the removal of skin flakes and some are thought to have antifungal properties.
• Severe dandruff may require a type of prescription shampoo or topical medications such as ketoconazole antifungal shampoo. Ketoconazole is available over the counter in a solution that is not as strong as the prescription shampoo.   

Scalp Psoriasis

Scalp psoriasis is not as easy to treat as dandruff.

• Mild cases of scalp psoriasis may also be treated with over-the-counter medicated shampoos. Prescription shampoo with corticosteroids—such as Clobex—may be used to help reduce inflammation caused by scalp psoriasis. The corticosteroids will also help to reduce inflammation.
• When a person has severe psoriasis, the treatment will most likely involve systemic (involving the entire body) medications, such as oral (by mouth) medications like methotrexate. Methotrexate works to suppress the overactive immune system that causes symptoms of psoriasis in very severe cases.

Another aspect of psoriasis treatment involves eliminating triggers such as:

• Tobacco
• Alcohol
• Stress
• Infections
• Extreme temperatures

When to See a Doctor

If your dandruff symptoms are mild, you may not need to see a doctor.

You should see a doctor when:

• It’s been several weeks since you started using a dandruff shampoo and there is no improvement in symptoms.
• The skin on your scalp is very swollen and red or starts to drain pus or fluid.
• The symptoms have spread to other parts of your body (other than just the scalp, particularly if symptoms spread to areas that don’t have hair).
• Your symptoms are accompanied by hair loss.

You should consult with a dermatologist any time you are living with psoriasis symptoms.

Consult with your healthcare provider if:

• Symptoms are worsening or your disease begins to flare up
• Treatments are not effective (either home treatment or prescription medication)

Prognosis

Dandruff

Although dandruff is not curable, the outlook/prognosis is good. Dandruff symptoms are usually controllable using medicated shampoo.

Scalp Psoriasis

The outcome of psoriasis treatment depends on several different factors. Like dandruff, psoriasis is not curable. Unlike that condition, however, psoriasis is often difficult to manage and flare-ups are known to occur throughout one’s lifetime.

Frequently Asked Questions

Can dandruff turn into psoriasis?

No, dandruff can't turn into psoriasis. They are two different things.

What does scalp psoriasis feel like?

Symptoms often experienced in those with scalp psoriasis include:

• Itching
• Burning
• Discomfort

Is it OK to scratch your head if you have scalp psoriasis?

Do not scratch your head if you have scalp psoriasis. Doing so could irritate your condition further and lead to complications down the line.