Having an itchy, flaky scalp is a common problem for many people. However, before you can figure out how to treat the condition, you must identify the cause. Two conditions that can lead to an itchy scalp are psoriasis and seborrheic dermatitis:

  • Psoriasis is a chronic skin disease. It can cause skin cells to grow so quickly that they accumulate on the surface of the skin. Patches of rough, scaly skin can appear anywhere on the body, including the scalp.
  • Seborrheic dermatitis is a skin condition that can cause rough, scaly skin on the scalp and face. The common name for seborrheic dermatitis is dandruff. In babies, it’s called cradle cap.

Sex and gender exist on spectrums. For the purposes of this article, we use “male” and “female” to refer to a person’s sex assigned at birth. Learn more.

Psoriasis tends to be pink or red with silvery scales on those with light or fair skin tones. On medium skin tones it can appear salmon-colored and silvery-white scales. On darker skin tones psoriasis tends to be violet with gray scales. Or it can also appear dark brown and difficult to see.

The patches can appear anywhere on the body, especially on the elbows and knees. They can also show up on the scalp. The patches can be itchy or tender to the touch.

Seborrheic dermatitis is usually found on the scalp, but it can sometimes appear elsewhere. It causes itchy patches of scaly skin that may look a little greasy but can flake, especially if you scratch.

Seborrheic dermatitis may look different in individuals with skin of color. It tends to be red and scaly on those with light or fair skin tones. On medium and dark skin tones this condition may appear as curved or petal-like lesions along the hairline. It can also cause hypopigmentation or lightening of the skin.

In babies, seborrheic dermatitis may be crusty. Children and babies of color tend to not experience the typical cradle cap appearance of seborrheic dermatitis. Instead they often have redness, a rash, flaking, and hypopigmentation of the affected areas and folds of skin often accompanied by atopic dermatitis.

Babies may also have seborrheic dermatitis around the eyes and nose. If the skin is scratched, there’s some risk of bleeding or infection if the thick scale is picked or removed from the scalp.

Psoriasis and seborrheic dermatitis of the scalp share some common symptoms. They both result in:

  • scaly patches of skin
  • flakes that may attach to the hair shaft
  • itching

How can you tell the difference? One clue is the scales. Psoriasis on the scalp on lighter skin tones often appears as red or pink and can have silvery-white scales. On darker skin tones, psoriasis is more likely to appear as dark or reddish brown or purple patches with overlying whitish or grayish scales.

The scales of seborrheic dermatitis are usually thinner. On lighter skin tones the scales are more likely to be pinkish-yellow with yellowish flakes, with a greasy appearance. In individuals with medium and dark skin tones, redness may be seen alongside flaking. Sometimes, the areas that are involved are lighter or darker than the individual’s normal skin tone.

As for the patches, if you have psoriasis, it’s likely that you have them on other parts of your body. If you scratch or try to remove them, they’ll probably bleed and also become thicker and itchier.

Seborrheic dermatitis patches are usually easy to remove, unless the pink patch which requires treatment. Psoriasis patches sometimes feel sore or tender, but seborrheic dermatitis doesn’t.—updated CSG

It’s possible to have both scalp conditions at the same time.

Anyone can get psoriasis of the scalp. There’s no way to prevent it. It’s more likely to occur in adults who have psoriasis elsewhere on their body.

The exact cause of psoriasis isn’t known, but it involves an overreaction of the immune system. It tends to run in families, so it’s likely there’s a genetic link.

Anyone can get seborrheic dermatitis, too. However, males develop it more often than females.

Some things that may play a role in developing seborrheic dermatitis include:

  • a family history of seborrheic dermatitis
  • oily skin
  • using alcohol-based products
  • weather extremes
  • stress
  • fatigue

Treatment may depend on the severity of your condition. Everyone responds differently to medication, so it may take a few tries to find the right solution for you.

Black, Indigenous, and People of Color patients may require a different treatment approach that takes into account differences in hair texture and hair washing frequency.

For some people, dandruff clears up on its own. Over-the-counter (OTC) shampoos and medication are usually enough to improve flaking and soothe itching. If not, ask your doctor about prescription-strength products.

In babies, cradle cap doesn’t always require treatment. It generally resolves well before the first birthday. In the meantime, use a mild baby shampoo. Massage the scalp gently using a very soft brush. Be gentle — breaking the skin can lead to infection. If you’re concerned about your baby’s scalp, see their pediatrician.

Psoriasis of the scalp may be harder to treat. Topical corticosteroids may help reduce inflammation and slow the growth of skin cells.

Psoriasis can also be treated with light therapy. Systemic treatment may be beneficial for stubborn psoriasis. This may involve oral treatments or injectable medications. It may take a combination of treatments to get psoriasis under control.

If you have a mild case of flaky skin on your scalp, OTC dandruff products may help. If they don’t, have your doctor take a look. Also see your doctor if you have undiagnosed patches of skin that look abnormal in other places on your body.

Your doctor will likely be able to tell whether it’s psoriasis, seborrheic dermatitis, or something else just by examining your skin. It might take looking at a skin sample under a microscope to confirm a diagnosis. In rare cases, a biopsy is needed.

Both seborrheic dermatitis and psoriasis are chronic, lifelong conditions. But with a proper diagnosis, you can monitor and effectively manage them.