Scalp Psoriasis vs. Dandruff: How to Tell the Difference (With Pictures)
Key takeaways:
Scalp psoriasis and dandruff are both common conditions that can cause an itchy and flaky scalp. They can be hard to tell apart.
Scalp psoriasis causes raised, scaly patches that are red, violet, or brown — depending on your underlying skin tone. Psoriasis can also spread to the hairline or surrounding skin.
Dandruff causes yellow or white greasy flakes. It may also affect eyebrows and other areas of facial hair, like a mustache or beard.
Both conditions can be treated with over-the-counter (OTC) medicated shampoos and prescription-strength shampoos, foams, or liquids.
Table of contents
Scalp psoriasis and dandruff have many similarities. They can both cause scalp itching and flaking, and telling them apart isn’t always easy. Knowing which condition you have is important, however, because the treatments for each one are different.
So, if you notice white flakes in your hair or on your shoulders, how do you know if it’s psoriasis or dandruff? Here are some tips for telling the two conditions apart — and what your treatment options are.
What is scalp psoriasis?
Psoriasis is a common condition that causes an itchy skin rash on different parts of the body. It develops when an overactive immune system causes skin cells to grow faster than normal. It’s not known exactly why this happens in some people and not others. Like many autoimmune conditions, it likely comes down to a combination of your genes and things you are exposed to in your life (like an infection).
About half of people with psoriasis will have it on their scalp, which can lead to itching and flaking. Some people may experience psoriasis on other parts of their body. But psoriasis affects more than the skin. Many people who have it will also develop psoriatic arthritis (inflammation of the joints).
No matter where you have it, psoriasis is a chronic condition that doesn’t go away on its own.
What is dandruff?
Dandruff is a common condition that causes small pieces of dry skin to flake off the scalp. Most people notice flakes in their hair or on their shoulders. It may be more obvious with dark hair or on dark clothes. Sometimes, dandruff can also cause the scalp to itch.
It’s not clear exactly what causes dandruff. One theory is that it’s the result of the immune system’s overreaction to a normal skin yeast called Malassezia. But it’s not considered an autoimmune condition. Dandruff is also a chronic condition. But unlike psoriasis, it only affects the skin.
Differences between dandruff and psoriasis
Scalp psoriasis and dandruff may seem similar, but they have some important differences. Here’s what to look for with these two common conditions.
Psoriasis | Dandruff | |
|---|---|---|
Appearance | In darker skin: violet or brown raised plaques with dry, silvery scales In fairer skin: pink or red raised plaques with dry, white scales Can lead to temporary hair loss | White or yellow flakes in scalp that can appear greasy Can also have oily or greasy hair Doesn’t usually lead to hair loss |
Location | Common in the scalp. Often extends to the hairline and nearby skin Other common locations include the elbows, knees, and lower back | Mainly in the scalp Eyebrows and facial hair in some people |
Symptoms | Itching (often intense) and flaking Sometimes burning, pain, or bleeding (when it’s scratched) | Mild itching and flaking |
Good to know | Nail changes and joint pain are common Associated with heart disease and diabetes | Some people have a more severe form with thicker flakes called seborrheic dermatitis |
What do scalp psoriasis and dandruff look like?
Scalp psoriasis looks like raised patches, usually with dry, white, or silvery scales overlying the rash. You may notice psoriasis extending into the skin at the hairline, neck, and around the ears. You may also notice patches or hair loss.
With dandruff, skin flakes tend to look more yellow and greasy. It’s common for people with dandruff to have oily or greasy-looking hair. And they may also have dandruff in their eyebrows and beard (if they have one). Dandruff doesn’t affect hairless skin.
Diagnosing scalp psoriasis and dandruff
To the trained eye, diagnosing psoriasis versus dandruff is usually pretty straightforward, based on your symptoms and what the rash looks like. Your dermatologist or healthcare professional may also examine the rest of your skin to see if you have signs of psoriasis on other parts of your body. In some situations, they may take a small skin biopsy from your scalp to send to the lab and confirm the diagnosis.
Best treatments for scalp psoriasis
Most scalp psoriasis can be treated with topical medications. These are treatments you apply directly to the scalp, like shampoos, foams, or liquids. For mild cases, medicated over-the-counter (OTC) shampoos that contain salicylic acid (like DHS Sal Shampoo) or coal tar (like Neutrogena T/Sal) may be enough to manage symptoms.
Prescription topical treatments for scalp psoriasis
For more stubborn psoriasis, prescription-strength topical treatments may be needed. Some good options include:
Steroid shampoos, foams, or solutions (liquids), like clobetasol shampoo (Clobex) or fluocinonide solution (Vanos)
Vitamin D analogs, like calcipotriene solution (Dovonex)
Combination products, which combine a steroid and vitamin D analog, like Taclonex (betamethasone / calcipotriene suspension)
Other treatments for scalp psoriasis
Localized light therapy (called the excimer laser) is another option to treat scalp psoriasis. It’s a painless treatment that delivers ultraviolet B (UVB) light to your scalp. You have to have this treatment 2 to 3 times a week at your doctor’s office.
If scalp psoriasis doesn’t respond to these treatments, you may need stronger treatment with pills or injectable medications. This isn’t common, but it’s an option for people with severe psoriasis, or those who also have psoriatic arthritis.
Best treatments for dandruff
Most dandruff can be controlled with OTC dandruff shampoo. Start by using the shampoo every 1 or 2 days. Once symptoms improve, use it less often to maintain the effect. Look for shampoos with these active ingredients:
Pyrithione zinc
Selenium sulfide
Ketoconazole 1%
Coal tar
Salicylic acid
Prescription treatments for dandruff
If dandruff doesn’t respond to OTC treatments, your healthcare professional may recommend prescription-strength shampoos or creams to control the flaking. Possible ones include:
Steroid shampoos, foams, or solution (liquids), like fluocinolone shampoo (Capex) or clobetasol foam (Olux)
Antifungal shampoos, like ketoconazole (Nizoral)
Selenium sulfide shampoos, like Selseb
The bottom line
An itchy and flaky scalp could be dandruff — but it might not be. Scalp psoriasis can cause similar symptoms too. Even though symptoms can be hard to tell apart, these are two very different conditions. Getting the diagnosis right helps you get the right treatment to get rid of scalp itch and flakes.
Why trust our experts?
References
American Osteopathic College of Dermatology. (n.d.). Biopsy.
Clark, G. W., et al. (2015). Diagnosis and treatment of seborrheic dermatitis. American Family Physician.
Merola, J. F., et al. (2018). Underdiagnosed and undertreated psoriasis: Nuances of treating psoriasis affecting the scalp, face, intertriginous areas, genitals, hands, feet, and nails. Dermatologic Therapy.
