Your doctor can usually tell whether you have scalp psoriasis, seborrheic dermatitis or both based on an examination of your skin, scalp and nails.

Scalp psoriasis and seborrheic dermatitis are common conditions that affect the scalp. In addition, they share some similar signs and symptoms, such as red, scaly skin.

Most often, the scales of psoriasis are thicker and somewhat drier in appearance than are the scales of seborrheic dermatitis. Psoriasis has more of a tendency to extend beyond the hairline. In addition, psoriasis usually affects more than one area of the body. If you have scalp psoriasis, you may also have mild psoriasis on your elbows, knees, hands or feet or may notice subtle nail changes, such as pitting.

Compare signs and symptoms

Scalp psoriasis

• Red skin covered with flakes and silvery scales
• Patches that may extend beyond the hairline or appear on other parts of the body
• Itching or soreness

Seborrheic dermatitis of the scalp

• Red skin covered with greasy-looking white or yellowish scales
• Skin flakes (dandruff) that may attach to the hair shaft
• Possibly itching

Scalp psoriasis and seborrheic dermatitis of the scalp share some similar treatments, including medicated shampoos and topical corticosteroid or antifungal solutions. Scalp psoriasis is often persistent and more difficult to treat than is seborrheic dermatitis of the scalp. Additional treatments, such as phototherapy, may be required to bring psoriasis under better control.