Scalp eczema affects the scalp and hairline. Like other forms of eczema, it causes dryness, itching and inflammation. It can be difficult to diagnose because other scalp conditions like psoriasis or fungal infections can cause similar symptoms.
Seborrheic dermatitis (aka dandruff) is the most common form of scalp eczema: about 3–10 of 100 people are affected. It is more common in men than in women, and people usually develop the scaly rash for the first time either in their early adulthood or later in life, typically over the age of 50. This condition can also occur in young children, known as cradle cap.
Scalp eczema typically falls into three main types — atopic dermatitis, contact dermatitis and seborrheic dermatitis — each with its own causes and approaches to treatment.
- Contact Dermatitis: This includes both irritant and allergic forms. Irritant contact dermatitis occurs when substances like detergents, shampoos, soaps, dyes, bleach or hair products damage skin cells, while allergic contact dermatitis occurs when allergens such as hair dye, preservatives or fragrances trigger flaking, swelling and itching.
- Atopic Dermatitis: This is the most common type of eczema, resulting from an overactive immune response that causes inflammation, weakens the skin barrier and leaves the skin dry, itchy and prone to rashes. These rashes may appear purple or brown in darker skin and red or pink in lighter skin.
- Seborrheic Dermatitis: This form of eczema appears in areas rich in sebaceous or oil-producing glands, such as the scalp, causing greasy, yellowish flakes and redness. In infants, this skin condition is known as cradle cap. It may come and go in both children and adults due to genetics, environmental factors or an inflammatory reaction to Malassezia, a naturally occurring yeast on the skin.
