Seborrheic Dermatitis Scalp: Symptoms, Causes & Hair Loss

Seborrheic dermatitis of the scalp is a common, long-lasting skin condition that causes red, itchy skin and greasy or white-yellow flaking on the oily parts of the head. It is not contagious, it is not caused by dirty hair, and it can be controlled with treatment but not cured.

The flaking is often mistaken for plain dandruff, and the red patches can look like scalp psoriasis. This guide explains what the condition is, what causes it, how to tell it apart from dandruff and psoriasis, which treatments doctors use, whether it makes hair fall out and what it means if you are thinking about a hair transplant.

A doctor can usually recognise it by how it looks and where it sits, so a skin test is rarely needed. The sections below show what to look for.

What Is Seborrheic Dermatitis of the Scalp?

Seborrheic dermatitis is an inflammatory skin condition that affects the "oily" areas of the skin, the places with many oil glands. The American Academy of Dermatology (AAD) describes it as a common condition that causes a scaly rash on oily areas such as the scalp and face. The British Association of Dermatologists (BAD) says the word "seborrhoeic" refers to the greasy, or sebaceous, skin zones such as the face, scalp, centre of the chest and back.

DermNet, a clinical reference run by dermatologists in New Zealand, calls it a chronic or relapsing condition and gives a figure of about 3% to 12% of people affected.

It also has other names. You may see it written as seborrhoeic dermatitis (the UK spelling), seborrheic eczema, "seb derm" or, in babies, cradle cap. They describe the same condition.

Three points are worth knowing from the start:

• It is not an infection you can catch. The AAD states plainly that seborrheic dermatitis is not contagious.
• It is not a hygiene problem. The AAD says it is not caused by unclean skin, and the NHS says dandruff in general is not caused by poor hygiene.
• It comes and goes. It tends to relapse, which is why long-term management matters more than a single course of shampoo.

Seborrheic dermatitis is most likely to start in one of three life stages, according to the AAD: infancy (2 to 12 months of age), adolescence, or adulthood, usually from the 30s onward. The AAD also notes that men are more likely to have it than women worldwide.

Seborrheic Dermatitis Scalp Symptoms

The signs vary from a few flakes to thick, crusted patches. The AAD lists dry, flaky skin that is more noticeable where there is hair or a rash, and the NHS describes scaly, itchy and red patches on the scalp, face and other areas. The BAD adds that the skin can look red, lighter or darker than the surrounding skin, with yellow flaking on the surface.

Typical signs on the scalp include:

• White or yellowish flakes that fall onto the shoulders, often worse on dark clothing
• Greasy-looking scale stuck to the scalp
• Red or discoloured skin underneath the scale
• Itching
• Patches that spread beyond the hairline

The rash is not limited to the head. In adults the AAD lists the forehead, the skin between and underneath the eyebrows, the eyelids, behind and inside the ears, the sides of the nose, the beard area, the back of the head and neck, and the chest. If your scalp is itchy and nothing else is going on, our guide to the causes of an itchy scalp covers the other possibilities.

What Causes Seborrheic Dermatitis?

The exact cause is not fully known. The AAD says yeast that lives on the skin and the skin's own oil (sebum) play a role. The yeast is called Malassezia, and it is a normal resident of healthy skin.

The BAD explains that in seborrheic dermatitis the yeast is found in higher amounts, and that current thinking points to a weakened skin barrier and extra sensitivity to oleic acid, a fatty acid the yeast produces, which results in inflammation. DermNet adds that Malassezia enzymes split fatty acids from sebum, and these may trigger the inflammation.

A review of the Malassezia genus in the journal Clinical Microbiology Reviews (Gaitanis and colleagues, 2012) notes that the exact role of the yeast in aggravating the condition is still under investigation, so the picture is not settled.

Two things follow from this:

• It is a reaction, not an infection. The BAD points out that the yeast on the skin is not the same as the yeasts that cause thrush or that are found in food.
• It is not an allergy. The AAD says seborrheic dermatitis is not an allergy.

Some people are more prone to it. The AAD lists Parkinson's disease, epilepsy, HIV infection, lymphoma, depression, Down syndrome, heavy alcohol use, and having rosacea or psoriasis. DermNet also lists oily skin and a family tendency. If you want the yeast side explained in more detail, read our page on a scalp yeast infection.

Seborrheic Dermatitis vs Dandruff vs Scalp Psoriasis

These three are the ones people confuse most. A review by Borda and Wikramanayake (2015) describes dandruff and seborrheic dermatitis as points on one continuous spectrum, and the AAD says dandruff may be considered the mildest form of seborrheic dermatitis. The difference is inflammation: according to the AAD, seborrheic dermatitis involves inflammation, dandruff does not.

Sources: AAD, NHS, BAD and DermNet pages listed under References.

Sometimes a person has both seborrheic dermatitis and psoriasis, which the AAD calls sebopsoriasis. If you are not sure which one you have, a dermatologist can tell, and a skin biopsy can be suggested when the diagnosis is in doubt (BAD). Our dedicated page on scalp psoriasis covers that condition in full.

One more look-alike is worth naming. The NHS lists scalp ringworm (tinea capitis) as a cause of a red or silver scalp rash, sometimes with patchy hair loss. If you see bald patches along with scaling, do not assume it is seborrheic dermatitis.

What Triggers a Flare?

A flare is a period when symptoms get worse after a calmer spell. The AAD says flare-ups are often seasonal, with most occurring in winter and early spring, and that many people also flare when stressed. The BAD lists tiredness, stress and cold, dry weather as triggers.

The AAD names these common triggers:

• Stress
• Cold, dry weather
• Hot showers and baths, especially in cold, dry weather
• Harsh detergents, strong soaps, solvents or chemicals on the skin
• Becoming sweaty
• Skin and hair products that contain alcohol

The AAD recommends alcohol-free skin and hair care products for this reason. Keeping a short diary of what you used, how stressed you were and what the weather was like can show your own pattern, and a pattern is worth showing your doctor.

Does Seborrheic Dermatitis Cause Hair Loss?

The honest answer is that it is not established as a direct cause of permanent hair loss, but the two are linked in studies. Neither the AAD nor the BAD pages lists hair loss as a feature of seborrheic dermatitis, while the same organisations describe hair loss separately as a different problem.

What research does show is an association with pattern hair loss. A 2025 study in the Indian Dermatology Online Journal (Menteşoğlu and colleagues) examined 311 adults with androgenetic alopecia and found seborrheic dermatitis in 131 of them (42.1%). The seborrheic dermatitis severity scores rose significantly as the hair loss became more severe, although the rise in how many people had it was not statistically significant.

The authors note that the study was small and cross-sectional, which means it cannot show that one causes the other. They conclude that seborrheic dermatitis may affect the way pattern hair loss develops and how severe it becomes.

In practice this means:

• Flaking and redness on a thinning scalp are worth treating, because inflamed skin is not a healthy base for hair.
• Treating the scalp will not reverse genetic thinning. Pattern hair loss needs its own assessment.
• Sudden shedding is a separate topic. See telogen effluvium and our overview of the reasons for hair loss.

Our page on whether dandruff causes hair loss goes deeper into the flaking side of this question.

Seborrheic Dermatitis Scalp Treatment

Treatment aims to calm the yeast and the inflammation and to keep flares away. The AAD says there is no cure, but treatment can help. Which product suits you, how strong it should be and how often it should be used is for a doctor or dermatologist to decide, so this section describes the types only.

The main groups in the AAD and DermNet pages are:

• Medicated shampoos. These include anti-dandruff shampoos and tar shampoos. The AAD warns that tar shampoos can discolour light, bleached or tinted hair.
• Antifungal products. Topical antifungals act on the yeast. The AAD notes that the FDA has approved topical ketoconazole for seborrheic dermatitis in people aged 12 and over with a healthy immune system.
• Zinc soap. The AAD says washing with zinc soap is often recommended.
• Keratolytics. DermNet lists these, which help loosen thick scale.
• Mild corticosteroids. The AAD says a dermatologist may add a corticosteroid if an antifungal or dandruff shampoo fails to clear the skin or scalp.
• Calcineurin inhibitors. DermNet lists these as another prescription option.

Corticosteroids need particular care. DermNet lists skin thinning from steroid use among the complications of treatment, which is a reason not to self-prescribe them. For the antifungal shampoo most people ask about, we have a separate page on ketoconazole shampoo, so it is not repeated here.

A doctor or dermatologist decides the treatment, and no online guide, including this one, can replace that.

Everyday Scalp Care

Self-care will not replace treatment, but it makes flares easier to manage. The AAD advice includes:

• Use alcohol-free skin and hair products, because alcohol can cause a flare-up
• Avoid very hot water, which can dry the skin and scalp
• Follow your dermatologist's advice on how often to shampoo
• Avoid harsh detergents, strong soaps and solvents

Do not scratch or pick at the scale. Doing so can irritate the skin, and DermNet lists secondary infection as a possible complication of the condition.

Seborrheic Dermatitis and Hair Transplant Timing

If you are planning a transplant, scalp condition matters, because the procedure is done on the scalp skin. We did not find a published guideline in the sources checked for this guide that sets a fixed waiting time between controlling seborrheic dermatitis and having a hair transplant, so we do not quote one.

What we can say is how the question is handled in practice at Turkey Hair Center. The medical team reviews clear scalp photos, asks about your diagnosis and your current treatment, and a doctor at the partner hospital examines the scalp before any plan is made. Turkey Hair Center is a Ministry of Health authorized health-tourism intermediary, and the procedure itself is carried out by its team in contracted hospitals and polyclinics in Istanbul.

Active redness, heavy scale or an unclear diagnosis are reasons for the doctor to ask for treatment or a dermatology opinion first.

If thinning is your main concern, the first step is working out whether the pattern looks like androgenetic alopecia. You can read how the FUE hair transplant works and what influences the hair transplant cost before you decide.

When to See a Doctor

Seek a dermatologist or your GP if:

• The scalp is red, swollen or painful. The NHS advises seeing a GP in this case.
• Symptoms persist after using an anti-dandruff shampoo (also NHS advice).
• You see bald patches, not just flakes.
• The rash is spreading to your face, ears or chest and you are not sure what it is.
• You think it might be psoriasis, which needs a different approach.
• Flares keep returning and are affecting your sleep or confidence. DermNet lists psychosocial impact among the effects of the condition.

This guide is general information and not a diagnosis or treatment plan. Medicines, shampoo strengths and how often to use them are decided by a doctor or dermatologist. See a doctor if the scalp is red, swollen or painful, if bald patches appear, or if symptoms do not improve.

Frequently Asked Questions

Worried About Thinning as Well as Flaking?

If your scalp is flaky and your hair also looks thinner at the hairline or crown, it helps to know which problem is which. Send clear photos for a free hair analysis, and the medical team will tell you what they see.

Medical disclaimer: This article is for informational purposes only and is not medical advice. Individual results and recovery vary from person to person. Always follow the written aftercare plan from your own medical team.