Seborrheic Dermatitis Scalp Guide for Stylists

Part of the USTI scalp health guide. Start with What is scalp health?

Seborrheic dermatitis on the scalp is a common skin condition that causes a scaly rash on oily areas of the body, according to the American Academy of Dermatology (AAD). It shows as flaking, scale and discolored skin, often with itch. It is not contagious, and it tends to come and go over time.

Stylists and barbers are often the first to notice when ordinary flaking has become something more. This field guide covers what the medical sources say, what you may see in the chair, how to adjust the service, what to say and when to refer. It builds on our overview of what scalp health is. Your role is to recognize, support and refer. Diagnosis and medical treatment belong to a physician.

What is seborrheic dermatitis on the scalp?

Seborrheic dermatitis is, in the AAD's words, "a common skin condition that causes a scaly rash on oily areas of the body like the scalp and face." DermNet describes it as a common, chronic or relapsing form of dermatitis that mainly affects areas rich in sebaceous glands: the scalp, face and trunk. DermNet puts its prevalence at 3% to 12% of the population.

Three points from the AAD help when a client is embarrassed:

• It is not contagious.
• It is not caused by unclean skin.
• It is not an allergy.

Cleveland Clinic calls it a lifelong condition that can come and go with flare-ups, and states there is no cure.

Who gets it?

The AAD says seborrheic dermatitis develops in people of all ages and races and is especially common in adults 50 years of age and older. It adds that men are more likely than women to develop it and that, in the United States, Black people are most likely to develop it. In babies it usually appears on the scalp and is called cradle cap.

What does Malassezia have to do with it?

The AAD says the exact cause remains unclear, and that dermatologists believe two things play a role: yeast that lives on everyone's skin, and sebum. The yeast is Malassezia. Cleveland Clinic says it is usually harmless, but that a skin reaction happens when there is too much of it. DermNet explains that enzymes made by Malassezia break down sebum into free fatty acids, which may induce inflammation. For more, see the scalp microbiome explained.

What does seborrheic dermatitis look like on the scalp?

The AAD describes a scaly rash with dry, flaky skin and itching or burning. It notes that the itch "is usually mild, but it can be intense, especially on the scalp." The National Psoriasis Foundation describes the look of the scale as yellowish and greasy.

What a stylist may notice during a normal service:

• Flakes on the scalp, in the hair and on the shoulders, together with skin that looks irritated or discolored.
• Scale that looks greasy or yellowish and sits on discolored skin.
• Patches at the hairline, behind the ears or at the back of the head and neck.
• Similar flaking in the eyebrows, the beard area or at the sides of the nose. The AAD lists all of these as common sites.
• A client who scratches often, or who says the scalp is worse in winter. The AAD notes that cold, dry weather can trigger flare-ups and that many people improve in warm, humid weather.

Seborrheic dermatitis in Black hair and skin of color

Redness is not a reliable sign on every client. The AAD says that in darker skin tones the scalp rash "tends to look pink, slightly purple, or lighter than your natural skin tone," and that some people with darker skin tones develop white spots on the scalp. In lighter skin tones, it says the rash is usually red and raised.

DermNet describes the same pattern as scaly hypopigmented patches, and names a petal-shaped presentation called petaloid seborrhoeic dermatitis.

Hair care habits matter here too. A 2023 paper in Skin Appendage Disorders by Mayo, Dinkins and Elewski notes that many patients of African descent lubricate the scalp with oils such as coconut oil, olive oil and shea butter, and that scale is often read as "dry scalp." The authors suggest hair oils may worsen seborrheic dermatitis in Black patients, and recommend keeping oils off the scalp and on the distal hair shaft. For a stylist, that is a reason to ask what goes on the scalp at home and to mention it in a referral.

Seborrheic dermatitis vs dandruff, psoriasis and dry scalp: what is the difference?

Seborrheic dermatitis and dandruff sit on the same spectrum. The AAD says dandruff "may be considered the mildest form of seborrheic dermatitis," and that the difference is inflammation: seborrheic dermatitis causes swelling and discolored skin, and dandruff does not. Psoriasis and dry scalp are separate problems that can also flake.

The table describes what the sources say about each. It is a recognition aid, not a way to diagnose. Conditions overlap, and the AAD notes that a dermatologist may take a skin biopsy when two conditions appear to be present.

For the everyday end of this spectrum, see dandruff vs dry scalp vs buildup. For the psoriasis column, see the scalp psoriasis guide for stylists.

Does seborrheic dermatitis cause hair loss?

Cleveland Clinic lists "hair shedding from scratching in affected areas (but not permanent hair loss)" among the symptoms of seborrheic dermatitis.

Do not assume that thinning on a flaky scalp is explained by the flaking. Note where the thinning is, how long the client has noticed it, and recommend a dermatologist. Our guide to hair shedding vs hair loss explains the distinction.

Can a hairstylist work on a client with seborrheic dermatitis?

In many cases, yes. The AAD states that seborrheic dermatitis is not contagious, so there is no risk of spreading it between clients. A routine cut, style or color is often possible when the skin is intact and the client is comfortable. Your state board rules and your salon's policy on inflamed or broken skin still apply.

Hold the service, or limit it to a dry cut away from the area, and refer when you see:

• Broken, bleeding, weeping or crusted skin.
• Pain, swelling or warmth.
• A client who has never had the scalp looked at by a physician.

Service adjustments within cosmetic scope

A stylist does not treat seborrheic dermatitis. What you can do is keep the service gentle and avoid making an irritated scalp worse.

1. Look first. Check the scalp in good light before you shampoo, and ask how it has felt lately. A structured approach is in the hair and scalp consultation guide.
2. Cleanse gently. Use the pads of the fingers, lukewarm water and light pressure. Do not scrub, pick or lift scale with a comb or a tool.
3. Rinse thoroughly. The AAD notes that cleanser left on the skin can irritate.
4. Go light on styling products at the scalp. The AAD advises patients to apply hair spray, gel and pomade sparingly and to choose alcohol-free hair care products.
5. Skip scrubs, peels and vigorous massage on inflamed skin.
6. Be cautious with chemical services during a flare. If the scalp is sore or broken, reschedule the color, relaxer or perm.
7. Ask about prescribed products and work around the client's schedule for them.
8. Record what you saw. A dated note or a photo, with consent, helps you and the client's physician see change over time.

How do you talk to a client about a flaky, inflamed scalp?

Describe what you see in plain words, remove the stigma, and point to a dermatologist. Do not name a condition.

A script you can adapt:

"I am noticing some flaking and a few patches where the skin looks irritated, here at the hairline and behind your ear. That is very common, and it has nothing to do with being clean. I cannot tell you what it is, but a dermatologist can, and there are effective options once you have a name for it. Today I will keep everything gentle around those areas."

Then ask two useful questions: how long it has been there, and what the client currently puts on the scalp at home. Both answers help the physician. If itch is the main complaint, our guide to itchy scalp causes covers the wider list.

When and how should you refer?

Refer any client with scale plus visible inflammation who has not seen a physician about it. Cleveland Clinic advises seeing a provider when the skin becomes painful, swollen or starts to drain fluid, when over-the-counter options are not helping, or when the condition affects daily life or mental health.

Refer promptly when you see:

• Thick, sharply edged plaques or silvery scale.
• Patches of hair loss, or broken hairs within a scaly patch.
• Pain, swelling, crusting or fluid.
• Rash that has spread to the face, ears or chest.
• Flaking that has not changed after weeks of regular washing.

A good referral is specific. Write down what you observed, where and when, and give it to the client to take along. See when to refer a client to a dermatologist for wording.

What a dermatologist may recommend, according to the AAD

The AAD says dermatologists diagnose seborrheic dermatitis by asking about symptoms, reviewing medical history and examining the skin. For the scalp, it says a dermatologist may recommend a dandruff shampoo for mild to moderate cases, used 2 to 3 times a week for straight or wavy hair, and possibly once a week for curly or tightly coiled hair. It also lists prescription options, including ciclopirox, ketoconazole and roflumilast foam.

These are medical decisions. Leave the choice of product and schedule to the client's dermatologist.

Where does this fit in a stylist's training?

The USTI Scalp Health & Hair Care Science Certification Program includes a module on common scalp diseases and a module on the flaking scalp in depth, covering dandruff, seborrheic dermatitis, psoriasis and atopic dermatitis, along with identifying when to refer.

Seborrheic dermatitis is common and not contagious. Recognize it, keep the service gentle, speak plainly and send the client to a dermatologist.

New to the field? Start with What is trichology? or look up a term in the trichology glossary.

Sources

• American Academy of Dermatology: Seborrheic dermatitis: Overview
• American Academy of Dermatology: Seborrheic dermatitis: Signs and symptoms
• American Academy of Dermatology: Seborrheic dermatitis: Causes
• American Academy of Dermatology: Seborrheic dermatitis: Diagnosis and treatment
• American Academy of Dermatology: Seborrheic dermatitis: Self-care
• American Academy of Dermatology: Scalp psoriasis: Signs and symptoms
• DermNet: Seborrhoeic dermatitis
• Cleveland Clinic: Seborrheic Dermatitis
• Cleveland Clinic: Dry Scalp
• National Psoriasis Foundation: Scalp Psoriasis
• Mayo T, Dinkins J, Elewski B. Hair Oils May Worsen Seborrheic Dermatitis in Black Patients. Skin Appendage Disorders. 2023;9(2):151-152
• Ranganathan S, Mukhopadhyay T. Dandruff: The Most Commercially Exploited Skin Disease. Indian Journal of Dermatology. 2010;55(2):130-134