Scalp Psoriasis vs Dermatitis: Know the Difference Scalp psoriasis and dermatitis are two different conditions that affect the scalp skin, but they often present similar symptoms. Knowing the difference between them is important for the proper diagnosis and scalp psoriasis treatment. Both conditions cause inflammation and discomfort, but their causes and treatments are different. Scalp psoriasis can be minimal, moderate, or severe. It may also extend to the scalp's periphery, including the hairline and the backside of the ear. Scalp dermatitis, commonly known as seborrheic dermatitis when it occurs on the scalp, is caused by the overproduction of oil and irritation from yeast that lives on the skin. It is not an autoimmune disease like psoriasis, and it tends to cause red, greasy, scaly patches, often accompanied by itching or flaking. Although scalp psoriasis and dermatitis cause the same symptoms—itching, flaking, and discomfort—there is a critical difference in their causes. Psoriasis is an autoimmune disease, and dermatitis is mainly caused by yeast, environmental factors, and other factors. Thus, scalp psoriasis treatment options may vary.