Eczema can result in inflamed, dry, itchy skin. On the scalp, skin may appear scaly and red, or a lighter color than the surrounding skin. A person may also experience dandruff.
One of the main types of eczema that can affect the scalp is seborrheic dermatitis. It appears in areas where the skin is most oily, such as the scalp, face, and upper back. When seborrheic dermatitis affects babies, it is known as cradle cap.
In this article, we look at risk factors for scalp eczema, how to prevent it, and what treatment involves.
Seborrheic dermatitis is a type of eczema
Doctors do not fully understand what causes seborrheic dermatitis, but a type of yeast that lives on the skin may be involved. Malassezia, this yeast, exists on everyone’s skin, and it may trigger an immune response in some people. This response leads to the inflammation and itchiness.
Seborrheic dermatitis affects up to
Seborrheic dermatitis can resemble dandruff, which is a milder condition that affects up to half of the population.
Certain factors can make people more prone to seborrheic dermatitis. These
- having oily skin
- being male
- living in a dry or cold environment
- having a condition that weakens the immune system, such as HIV
- having a neurological condition, such as Parkinson’s disease
- having certain mental health conditions, such as depression or an eating disorder
- taking certain medications, such as lithium, dopamine antagonists, or immunosuppressants
The following might trigger a flare-up of this type of eczema:
- lack of sleep
- dry skin
People can usually tell the difference between eczema and dandruff by looking for visible signs of inflammation. Both eczema and dandruff can cause flaky skin and itchiness, but only eczema typically causes inflamed patches of skin.
Researchers think that dandruff and seborrheic dermatitis are part of the same disease process and that both are related to the presence of Malassezia fungus on the scalp.
Scalp eczema causes patches of itchy, inflamed, dry skin. The patches may change in shape and size over time.
People with seborrheic dermatitis may also have:
- patches of waxy or oily skin
- skin that flakes off
- yellow or red discoloration, in people with lighter skin tones
- skin that is darker or lighter than the surrounding area, in people with deeper skin tones
The condition typically appears in areas with a lot of oil-producing glands. A person with seborrheic dermatitis on their scalp may also have it in other areas that produce oil, such as the:
- ear canal
- area behind the ears
- upper back
Even after the rash heals, any color changes may last.
The best approach depends on the type of eczema a person has. For seborrheic dermatitis, treatment involves using topical products that reduce the growth of the yeast, calm inflammation, and remove the flakiness.
The first step involves skin care, and a dermatologist can describe how to keep the scalp clean and hydrated. Replacing any harsh shampoos with gentle, pH-balanced ones may reduce irritation, for example.
Next, the doctor may recommend an antifungal cream, spray, or scalp treatment. This
- zinc pyrithione
- salicylic acid
- selenium sulfide
- coal tar
For more severe cases, a mild corticosteroid can calm the inflammation. A doctor may prescribe a topical corticosteroid, which goes on the skin, to treat an active flare-up that causes severe pain, itching, and flaking. Corticosteroids are not suitable for use over long periods, however.
A doctor may also prescribe a topical medication that suppresses the immune system. These products do not contain corticosteroids and a person can use them for longer periods. For very severe cases, doctors may prescribe an oral antifungal medication.
For babies with cradle cap, mineral oil can help loosen the flakes so that they fall off with gentle washing. Usually, this is all that is necessary. The condition often improves on its own after a few months.
In adults, seborrheic dermatitis can come and go for long periods and require managing to reduce flare-ups.
Many prescription products for seborrheic dermatitis contain ingredients that people can purchase over the counter, such as:
- coal tar, which reduces itching
- sulfur, an antibacterial mineral
- salicylic acid, a compound that naturally occurs in plants and exfoliates flaky skin
Many over-the-counter scalp treatments contain these substances.
Also, some research shows that daily use of a 5% tea tree oil shampoo can significantly improve mild-to-moderate symptoms without causing side effects. However, less research has gone into this approach.
People should never use essential oils undiluted on the skin. Also do not use these oils at all to treat eczema in children or babies.
There is no single test for scalp eczema. The yeasts that play a role in seborrheic dermatitis occur naturally on everyone’s scalp, so testing for these will not help.
Instead, a doctor does a physical examination and takes the person’s medical history. They may diagnose eczema based on the symptoms alone, or they may perform tests to rule out other possibilities, such as an allergic reaction.
The specific symptoms can also reveal the type of eczema.
If a doctor suspects a fungal infection, they may take a skin scraping and send it for analysis.
- avoiding contact with harsh soaps, chemicals, or solvents
- protecting the head in cold or dry weather
- using a humidifier to make indoor air less dry
- washing the scalp after exercise and other activities that cause sweating
- reducing and managing stress levels
- receiving treatment for any medical conditions that increase the risk of seborrheic dermatitis
If a medication may be contributing to scalp eczema, a doctor can describe the next steps.
Seborrheic dermatitis is a type of eczema that
Treatment may involve using topical creams, sprays, or shampoos that contain antifungal and anti-inflammatory ingredients.
Because other types of eczema can also occur on the scalp, it is important to get a diagnosis. The doctor can also rule out other conditions that can cause an inflamed or flaky rash, such as psoriasis.