Seborrheic dermatitis

Seborrheic dermatitis is a common, long-lasting skin condition. It causes flaky or scaly patches in areas with many oil-producing glands. These include the scalp, eyebrows, sides of the nose, ears, eyelids, chest, and skin folds.

The scales may look dry and white or greasy and yellow. The skin underneath can be inflamed and itchy. Redness may be less noticeable on brown or black skin, where affected areas may instead look darker, lighter, purple, or grey.

Seborrheic dermatitis is not caused by poor hygiene. It is not contagious, so you cannot catch it from or pass it to another person.

In babies, seborrheic dermatitis of the scalp is usually called cradle cap. It often clears during infancy. In teenagers and adults, the condition commonly follows a cycle: symptoms improve and then return. Treatment can usually control these flares, but it does not permanently remove the tendency to develop them.

Symptoms usually develop in oily areas of the skin. They can affect one area or several areas at the same time.

Common features include:

• White, grey, or yellow flakes
• Greasy or crusted scales
• Itching or mild soreness
• Inflamed skin beneath the scales
• Flaking around the eyebrows, nose, ears, or beard
• Dandruff on the scalp, hair, or clothing
• Scaling along the eyelid edges

Scalp symptoms range from mild dandruff to thick, widespread scaling. Scratching may cause small breaks in the skin.

On darker skin, seborrheic dermatitis may cause areas of lighter or darker colour. These changes can remain for a while after the inflammation settles. They do not always mean the condition is still active.

Cradle cap causes greasy, yellowish, or brown scales on a baby’s scalp. It may also affect the face, behind the ears, the neck, or the nappy area. Babies are often otherwise comfortable, although some have mild redness.

Symptoms may become more noticeable during cold, dry weather, periods of stress, illness, or tiredness. Sweat and irritating hair or skin products can also worsen symptoms for some people.

The exact cause is not fully understood. Seborrheic dermatitis appears to involve a combination of skin oil, the immune system, and a yeast called Malassezia.

Malassezia normally lives on human skin and is not usually harmful. In people with seborrheic dermatitis, the skin may have an inflammatory response to this yeast or to substances produced when it breaks down skin oils.

The condition is not simply the result of having oily skin. Washing more often does not cure it, and harsh scrubbing can make inflammation worse.

Seborrheic dermatitis can occur at any age. It is especially seen during early infancy and from adolescence onward. Adult symptoms may be more persistent in people who have certain neurological conditions, such as Parkinson’s disease, or a weakened immune system, including from HIV infection. Having seborrheic dermatitis does not mean that you have one of these conditions.

Stress, cold weather, low humidity, and some irritating products may trigger a flare. These factors do not create the underlying condition.

A healthcare professional can usually diagnose seborrheic dermatitis by looking at the affected skin and asking about your symptoms. There is no single blood test or scan that confirms it.

The location and appearance of the rash help distinguish it from other conditions. Psoriasis may form thicker, more sharply defined scales. Eczema is often drier and may appear in different areas. A fungal infection such as ringworm can cause patchy hair loss or a ring-shaped rash.

If the appearance is unusual or treatment has not helped, testing may be needed. A small scraping can be examined for a fungal infection. Rarely, a small skin sample called a biopsy is taken to rule out another condition.

Widespread or unusually severe seborrheic dermatitis may lead a clinician to ask about medicines, general health, or conditions that affect the immune system. This does not mean that a serious cause is always present.

Treatment aims to remove scale, reduce yeast on the skin, calm inflammation, and limit future flares. The best option depends on the affected area, your age, and how severe the symptoms are.

Medicated dandruff shampoos are often used for the scalp. Their active ingredients may include an antifungal such as ketoconazole, or substances such as selenium sulfide, salicylic acid, or coal tar. Different products work in different ways. Following the product instructions matters because some need time on the scalp before rinsing.

Once symptoms are controlled, occasional maintenance use may help reduce relapses. A pharmacist or clinician can help you choose an appropriate product, especially for a child, during pregnancy, or if you have sensitive or broken skin.

For the face, ears, chest, or skin folds, treatment may include an antifungal cream. A clinician may recommend a mild corticosteroid like prednisone or hydrocortisone for a short period when inflammation is troublesome. Corticosteroids reduce redness and itching, but repeated or prolonged use can thin the skin, especially on the face and around the eyes.

Non-steroid anti-inflammatory creams called topical calcineurin inhibitors are sometimes used on sensitive areas. They can cause temporary warmth or stinging but do not cause the same skin thinning as corticosteroids. They require professional guidance in some countries.

For eyelid scaling, gentle cleaning of the eyelid edges and warm compresses may help. Eye pain, marked swelling, light sensitivity, or changes in vision need medical assessment rather than self-treatment.

Cradle cap can often be managed by washing the scalp with a mild baby shampoo and gently loosening scales with a soft brush. An emollient may be used briefly to soften thick scale before washing it away. Do not pick the scales or leave oily products on the scalp for long periods. A clinician may suggest an antifungal or mild anti-inflammatory treatment if cradle cap is persistent, inflamed, or widespread.

Try to avoid scratching and harsh scrubbing. Fragranced or alcohol-based products may sting inflamed skin. If a new treatment causes worsening redness, burning, swelling, or blistering, stop using it and seek advice.

Seborrheic dermatitis usually does not cause serious physical complications. Persistent itching can disturb sleep or make it difficult to concentrate.

Scratching can break the skin and allow a bacterial infection to develop. Signs may include increasing pain, warmth, swelling, pus, or rapidly spreading redness.

Inflammation and scratching of the scalp can sometimes increase hair shedding. This is usually temporary once the scalp improves. Patchy hair loss, broken hairs, or scarring are not typical and should be assessed for another cause.

Changes in skin colour may remain after a flare, particularly on darker skin. These changes often fade slowly over weeks or months, although the timing cannot be predicted.

Visible flakes or facial patches can affect confidence and social comfort. If the condition is affecting your mood, sleep, work, or relationships, this is a valid reason to discuss further treatment.

Seborrheic dermatitis cannot always be prevented. It reflects how your skin responds to normal yeast and skin oils, rather than something you have done wrong.

Once you know where symptoms tend to occur, a regular maintenance routine may reduce the number or intensity of flares. This may include using an effective medicated shampoo from time to time and choosing gentle, fragrance-free skin products.

Avoid known personal triggers when practical. These may include harsh hair treatments, heavy styling products, very hot showers, or leaving sweat against the skin. Stress management may help some people, but stress is not the sole cause and a flare is not a personal failure.

There is no specific diet proven to prevent seborrheic dermatitis. Avoiding foods without a clear personal reason can make eating unnecessarily restrictive.

Cradle cap usually improves within weeks or months and often resolves during the first year of life. Persistent, very itchy, or widespread rashes in a baby may need assessment because other forms of eczema can look similar.

In adults and teenagers, seborrheic dermatitis is usually a recurring condition. Some people have mild dandruff from time to time. Others have repeated facial or scalp flares that need ongoing maintenance.

The location of the condition often stays fairly consistent. A person who develops scaling around the nose and eyebrows may notice future flares in those same places. Symptoms can still change with the season, stress, illness, or treatment.

Treatment often starts to reduce scale and irritation over days to weeks, but recurrence is common after it is stopped. This does not mean treatment has failed. Maintenance care may keep symptoms controlled for longer.

Seborrheic dermatitis does not usually damage overall health. Most people continue their usual work, exercise, hair care, and social activities. It may take some trial and adjustment to find products that control symptoms without irritating the skin.

Arrange a routine appointment if:

• You are unsure whether the rash is seborrheic dermatitis
• Symptoms persist despite correctly used non-prescription treatment
• The rash is widespread, painful, or repeatedly disrupts sleep
• You have patchy hair loss, broken hairs, or thick plaques
• Eyelid scaling keeps returning
• A baby’s rash is very itchy, inflamed, spreading, or not improving
• Skin colour changes or visible symptoms are causing distress

Seek prompt medical advice if the skin becomes increasingly painful, warm, swollen, or begins leaking pus. Fever with rapidly spreading redness may indicate an infection and needs urgent assessment.

Eye pain, strong sensitivity to light, marked eyelid swelling, or changes in vision also need urgent assessment.

Call emergency services for difficulty breathing, faintness, or swelling of the lips, tongue, face, or throat after using a treatment. These can be signs of a serious allergic reaction and are not usual symptoms of seborrheic dermatitis.

Is seborrheic dermatitis the same as dandruff?

Dandruff is generally considered a mild form of scalp seborrheic dermatitis. It mainly causes loose flakes without much visible inflammation. Seborrheic dermatitis can cause more redness, irritation, and greasy or crusted scale, and it may affect areas beyond the scalp.

Is seborrheic dermatitis contagious?

No. The yeast linked with the condition normally lives on most people’s skin. Symptoms result from an individual skin response, not an infection that spreads between people. You do not need to avoid sharing space or physical contact.

Does seborrheic dermatitis cause hair loss?

It does not usually damage hair follicles. Inflammation, heavy scale, and scratching may cause temporary shedding. Hair generally grows normally after the scalp settles. Patchy loss, broken hairs, or scarring may suggest another condition.

Should I wash my hair more often?

Regular washing can remove oil and scale, but excessive washing or harsh scrubbing may irritate the scalp. Medicated shampoos must be used according to their instructions. Hair type, styling practices, and scalp sensitivity can affect which routine is practical.

Can seborrheic dermatitis be cured permanently?

Adult seborrheic dermatitis usually cannot be permanently cured. Treatment can control a flare, and maintenance care can reduce recurrences. Some people have long periods with few or no symptoms. Cradle cap often clears as a baby grows.

Is seborrheic dermatitis caused by stress or food?

Stress can trigger or worsen a flare in some people, but it is not the only cause. No particular food has been shown to cause seborrheic dermatitis in most people. A balanced diet is appropriate unless you have a separate, confirmed food-related condition.