Scalp Psoriasis Vs Dandruff: How to Tell the Difference

Both scalp psoriasis and dandruff produce small, white flakes which may be visible in the hair, neck and on the shoulders. The two conditions, however, are very different in terms how they are caused. Even more importantly: psoriasis and dandruff each require a unique course of treatment.

Since symptoms can be similar, properly differentiating between the two can be difficult. Here’s how to tell the difference between psoriasis and dandruff to ensure you’re treating your condition correctly.

About Scalp Psoriasis

Psoriasis is an auto-immune condition that affects the skin and musculoskeletal system. Although it can appear anywhere on the body, approximately 50% of those with psoriasis experience it on their scalp. It often appears as thick, scaly and silvery plaques.

What Causes Scalp Psoriasis?

Psoriasis results from immune system dysregulation, which leads to the overproduction of skin cells, often on the scalp. The skin’s epidermal layer proliferates instead of shedding, resulting in plaque formations.

While it’s unknown what leads to the auto-immune condition, stress, extreme temperature changes, and illness can all trigger the inflammation which leads to flare ups.

What are the Symptoms of Scalp Psoriasis? 

Scalp psoriasis appears as thick and inflamed silvery, scale-like plaques. In those with light skin, the scalp may appear reddish or pink, and in those with dark skin, it can appear purple.

Skin cells may shed and can be found in the hair, on the neck and on the shoulders, similar to dandruff. The condition may cause temporary patches of hair loss.

Flaking skin cells are often accompanied by sensations of burning or itching, which can be painful.

About Dandruff

Dandruff is a common scalp condition that also leads to dry, flakey skin that often ends up in hair, or falls to the neck and shoulders. Dandruff can be itchy and embarrassing, although unlike psoriasis, it doesn’t typically require medical attention.

What Causes Dandruff?

Dandruff is sometimes the result of dry skin, which can appear on the scalp just as it does on the body. However, it’s more likely the result of oily skin, which can flake off when not shampooed often enough. An oily scalp can also lead to the following conditions:

Yeast Infection: Yeast, specifically malassezia, is a type of fungus which is naturally found in parts of the body. An oily scalp can cause this fungus to overgrow, leading to dandruff.

Seborrheic Dermatitis: This skin condition develops as an inflammatory response to yeast, and results in oily, irritated skin flaking off in the scalp area. It is often accompanied by itchiness.

Contact Dermatitis: This condition is caused by irritants in hair care products which lead to inflammation, redness, and flaking. It’s often itchy.

Men’s scalps produce more sebum (oil) than women’s, making them more susceptible to dandruff.

What Are the Symptoms of Dandruff?

Dandruff presents as small flakes of skin that cling to hair and fall off onto the neck and shoulders. It’s often accompanied by itchiness.

Psoriasis vs Dandruff: The Differences

Since psoriasis and dandruff are treated differently, it’s important to receive a proper diagnosis. The list of differences below may help you self-diagnose. If you’re still unsure, or if you think you may have psoriasis, it’s best to see a doctor for confirmation.

Is it chronic? Dandruff may come and go, but scalp psoriasis tends to be more long-lasting.

Is it scaly or flaky? Scalp psoriasis often looks like silvery scales or plaques, which may or may not flake off. Dandruff tends to be more visible as flakes, versus plaques on the scalp itself.

Is it oily or dry? Psoriasis tends to result in dry plaques, while dandruff is more often the result of oily, greasy hair.

Is there redness? Dandruff’s white flakes aren’t normally accompanied by scalp redness. With scalp psoriasis, it’s common for light scalps to appear as pink or red, while darker scalps may appear as purple.

Is it spreading? Dandruff can also involve the face and neck, particularly when seborrheic dermatitis is the root cause. However, dandruff is highly unlikely to occur below the neck. Psoriasis, in contrast, can occur on nearly all parts of the body including areas below the neck.

Are there other symptoms? As an auto-immune condition, psoriasis is associated with inflammation-related issues including arthritic-like symptoms and cardiovascular risk.

Treatments for Scalp Psoriasis

If you have psoriasis, you should be under the care of a doctor who can assess what’s needed should the condition progress. There are two primary courses of action for psoriasis treatment, topical and systemic.

Topical Treatments for Psoriasis

The most common topical treatments include shampoos, ointments, foams and creams.

Shampoos typically include salicylic acid (as an exfoliator) or coal tar and work best in mild cases.

Corticosteroids are the most common treatment, and work well to reduce the inflammation that leads to scaling.

Vitamin D3 analogues are often used in combination with corticosteroids, or alone when scaling (not inflammation) is the condition’s primary feature.

Light or laser therapy can provide some patients relief, although it can be difficult to treat the scalp through thick hair.

Systemic Medications for Psoriasis

More severe cases of psoriasis may require systemic treatment with oral or injectable medications.

Corticosteroids can be injected directly into the scalp. This treatment, however, is not suitable for chronic cases.

Biologic medications are transferred from living cells and may help regulate immune system response, decreasing instances of flare ups.

Oral retinoids offer a strong dose of vitamin A, which can reduce swelling or redness and slow cell growth.

Immunosuppressants may be recommended for those with severe psoriasis or psoriatic arthritis.

As psoriasis often flares in response to stress, stress relief practices may help keep inflammation and flare ups at bay.

Treating Dandruff

Treating dandruff, especially mild cases, is often as simple as switching your shampoo or your shampooing routine.

For mild cases due to oily hair, wash hair consistently every 1-2 days with a gentle shampoo.

Shampoos specifically formulated for treating dandruff may include the following ingredients:

• Zinc pyrithione
• Coal tar
• Salicylic acid
• Selenium sulfide
• Ketoconazole
• Tea tree oil

Each works differently, so be sure to follow the directions on the label regarding how long to let the shampoo sit, and how often to use it.

For more severe cases, or cases that persist longer than one-month, topical anti-inflammatory medication prescribed by a doctor may be indicated.

Adam Smithee, MD is a Board Certified Dermatologist who grew up just up the road from Austin in Round Rock, Texas. Dr. Smithee is experienced in treating both adult and pediatric patients, from eczema to skin cancer to more complex dermatologic conditions. He is committed to treating all patients with a compassionate and patient centered approach while providing them with the most up to date information about their condition and treatment options.