Scalp Psoriasis

Scalp psoriasis is plaque psoriasis that shows up on the scalp. Like psoriasis anywhere else, it happens when the immune system sends faulty signals that make skin cells grow far too fast. Cells that should take weeks to renew do it in days, and the extra cells pile up as thick scale.

On the scalp, this looks like red or discolored raised patches covered in thick, silvery-white scale. It often spreads past the hairline onto the forehead, the back of the neck, and behind the ears. That hairline crossing is a useful clue — dandruff and dry scalp stay on the scalp.

About half of people with psoriasis get it on their scalp. For some, the scalp is the only place it shows up.

Red, raised patches. Inflamed, sometimes painful, covered with thick silvery-white scale.

Itching and burning. Can range from mild to severe. Some people describe it as burning rather than itching.

Flaking. Scale comes off in the hair and onto clothing, especially when scratched.

Dryness and tightness. The scalp can feel tight.

Bleeding. Scratching or picking at scale can cause small cuts and bleeding.

Temporary hair loss. Scalp psoriasis doesn't directly destroy hair follicles. But repeated scratching and picking can pull hair out. Once the condition is controlled, hair grows back.

Spreads past the hairline. Onto the forehead, behind the ears, and the back of the neck.

The same causes as psoriasis anywhere:

An overactive immune system. The immune system mistakenly targets healthy skin, creating inflammation that speeds up skin cell growth.

Genetics. Psoriasis runs in families.

A trigger. Genes load the gun; a trigger fires it. Common triggers are stress, infections, cold weather, certain medications, and skin injury (the Koebner phenomenon — psoriasis appearing right where the skin was hurt).

Stress. One of the most common triggers.

Scratching and picking. This is the big one for the scalp. It injures the skin, which triggers more psoriasis, which itches more. Breaking that cycle is a core part of treatment.

Cold, dry weather. Winter is usually worse.

Infections. Especially strep.

Harsh hair products. Can irritate an already inflamed scalp.

Overusing medicated shampoo. More is not better. Used too often or left on too long, medicated shampoos cause irritation, itching, and redness — which looks like a flare and makes you use more. Follow the directions.

A dermatologist can usually diagnose scalp psoriasis by looking at your scalp, skin, and nails. They will part your hair to look at the scalp directly, and check behind your ears and along the hairline.

They'll look for the features that separate it from dandruff: thick silvery scale, red raised skin underneath, sharp edges, and spread past the hairline.

They'll also check your nails and the rest of your skin, since scalp psoriasis often comes with psoriasis elsewhere. A biopsy is rarely needed.

Treating scalp psoriasis comes down to two steps. Do them in order.

Step 1 — Remove the flakes. Scale acts as a barrier. If you don't lift it, your anti-inflammatory treatment can't reach the skin underneath.

• Salicylic acid shampoo breaks down and lifts scale. Look for 3% salicylic acid (Neutrogena T/Sal, MG217, Dermarest).
• Oil before shampooing. Massage coconut or mineral oil into the scalp, let it sit 10–15 minutes to soften the scale, then wash it out thoroughly.
• Gentle combing after shampooing, when scale is soft. Be gentle — aggressive scraping injures the skin and triggers more psoriasis.

Step 2 — Reduce the inflammation.

• Coal tar shampoo slows skin cell growth and calms itch (Neutrogena T/Gel, Denorex, Tarsum). It smells strong, but it works.
• Anti-dandruff shampoos with zinc pyrithione, ketoconazole, or selenium sulfide help with both flakes and itch.
• OTC 1% hydrocortisone solutions calm redness and itch. Don't overuse.

Three tips that make a real difference:

Medicated shampoo is for your scalp, not your hair. Part your hair into sections and apply it directly to the roots. It does nothing sitting on your hair, and overexposing your hair to it just causes damage.

Leave it on. Most medicated shampoos need several minutes of contact to work. Lathering and rinsing immediately wastes the product.

Condition afterward. Medicated shampoos are drying. Follow with a moisturizing conditioner on the hair, not the scalp.

Shampoos that remove scale (salicylic acid, 3%)

Neutrogena T/Sal, MG217 Psoriasis, Dermarest Psoriasis, Nizoral Psoriasis. Use about twice a week and leave on several minutes before rinsing.

Shampoos that reduce itch and inflammation

• Zinc pyrithione (Head & Shoulders, Dove Dandruff) — gentle, fine for regular use and sensitive scalps
• Ketoconazole 1% (Nizoral Anti-Dandruff) — stronger antifungal, for stubborn flaking. Use 1–2 times weekly. A 2% prescription version exists.
• Selenium sulfide 1% (Selsun Blue) — good for oily flaking. 2–3 times weekly.
• Hydrocortisone 1% (Scalpicin, Nizoral Scalp Itch Relief) — a mild steroid for itch. Don't overuse.

Shampoos that do both (coal tar)

Neutrogena T/Gel (0.5%), Denorex (0.5%), DHS Coal Tar (0.5%), Tarsum Extra Strength (2%). Coal tar slows skin cell growth and calms itch. Strong smell, and it can stain fabric and light-colored hair.

Rotating between a scale-removing shampoo and an anti-inflammatory one often works better than relying on just one.

When shampoos aren't enough, prescription treatment helps. Scalp treatments come as solutions, foams, and oils rather than thick creams, because those spread through hair more easily.

Topical steroids. The mainstay. Come in solutions, foams, and shampoos designed for hair-bearing skin. Long-term use thins the skin, so they're used in cycles. Examples: clobetasol solution, betamethasone, fluocinonide, Bettamousse.

Vitamin D treatments. Slow skin cell growth, few side effects, often combined with a steroid. Examples: calcipotriene, Sorilux foam.

Otezla. A twice-daily pill for more widespread disease. Common side effect is diarrhea.

Sotyktu. A once-daily pill. Few side effects but needs monitoring.

Biologics. Self-injected at home, very effective for moderate to severe psoriasis, including stubborn scalp disease. Need regular monitoring. Examples: Humira, Stelara, Cosentyx, Skyrizi.

Prednisone. An oral steroid, used rarely and short-term only. Stopping suddenly can cause a severe rebound flare.

Phototherapy uses controlled UV light to calm inflammation and slow skin cell growth.

The scalp is harder to treat with light because hair blocks it. Special comb-shaped UVB devices exist to part the hair and deliver light directly to the scalp.

Office phototherapy. UVB delivered in a clinic, usually a few times a week.

Home phototherapy. A prescription device for home use. Check insurance coverage under "Durable Medical Equipment (DME)." National Biologic and SolRx are common suppliers.

OTC devices. Handheld units you can buy online, reasonable for mild to moderate disease on limited areas.

See a dermatologist if:

• Medicated shampoos aren't working after several weeks of correct use
• The scale is thick or the scalp is painful
• You're losing hair
• It's spread onto your face, ears, or neck
• The itch is disrupting your sleep
• You have joint pain or stiffness (this could be psoriatic arthritis)

Also worth going if you're not sure it's psoriasis at all. Scalp psoriasis, seborrheic dermatitis, and fungal infections are treated very differently, and treating the wrong one wastes months.

Dandruff (seborrheic dermatitis)
- Cause: yeast overgrowth
- Itch: mild to moderate
- Flakes: loose, white to yellow, often greasy
- Clue: stays on the scalp
- Treatment: antifungal shampoo

Scalp psoriasis
- Cause: overactive immune system
- Itch: moderate to severe, sometimes burning or soreness
- Flakes: thick, silvery-white scale on red, raised skin
- Clue: crosses the hairline onto forehead, neck, behind the ears
- Treatment: medicated shampoos, topical steroids, prescription treatment

Dry scalp
- Cause: lack of moisture
- Itch: mild
- Flakes: small, white, dry
- Clue: worse in cold weather or with harsh shampoos; no redness underneath
- Treatment: gentler shampoo, scalp moisturizer

The simplest tell: lift a flake and look at the skin underneath. If it's red and raised, think psoriasis. If it looks normal, think dry scalp.