The scalp is skin, with more oil glands than most of the body, so flaking, itching, oiliness and buildup are skin problems. Most cases trace to one of four causes: seborrheic dermatitis, psoriasis, dryness or product buildup, and each needs a different answer. Scalp conditions are evaluated and treated at Coastal Dermatology + Aesthetics in San Luis Obispo.
Your scalp is skin, and it behaves like it
Everything that happens to skin happens to your scalp. It gets dry, it gets oily, it reacts to what you put on it, and it develops the same conditions your face does. The difference is that it sits under hair, so you feel it long before you can see it, and by the time flakes are landing on your shoulders you have usually been managing it alone for a while.
It also has more oil glands than almost anywhere else on your body, which is why the conditions that thrive in oily skin turn up here first. That is the reason a scalp can be flaking and greasy at the same time, which feels contradictory and is completely ordinary.
Almost all of it comes down to four causes, and telling them apart is what the appointment is for. Three of the four are not solved by a bottle from the store, and knowing which one you have is the difference between a clear scalp in a few weeks and another year of trying shampoos.
What brings people in
- Flaking that comes back no matter which shampoo is tried
- Itching, sometimes intense, and usually worst on the scalp [2]
- A scalp that is oily again by the same afternoon
- Redness or scale that runs past the hairline, onto the face or behind the ears
- Soreness, tenderness or burning
- Buildup that feels like a film, particularly with fine hair or frequent styling
Flaking and itching on a scalp almost always comes down to one of four things: seborrheic dermatitis, psoriasis, plain dryness, or product buildup. They need four different answers.
What causes it
Seborrheic dermatitis
The most common cause, and what most people mean when they say dandruff. It thrives in oily areas, so it favors the scalp, the eyebrows, the sides of the nose and behind the ears. The rash can be dry, have greasy scales, or both, and the itch is usually mild, though it can be intense, especially on the scalp. [2] It looks different across skin tones: usually red and raised on lighter skin, and pink, slightly purple or lighter than your natural tone on deeper skin. [2]
Psoriasis, dryness and buildup
Scalp psoriasis produces thicker, more defined scale and is a different condition with a different treatment. Plain dryness flakes finely and improves with the right routine. Buildup is product and oil sitting on the skin, and it clears mechanically rather than medically. It is also possible to have two of these at once: seborrheic dermatitis and psoriasis together are common enough to have their own name. [1]
Why guessing does not settle it
All four flake. Several of them itch. Two of them can look almost identical under hair, which is why a dermatologist parts the hair and looks at the skin rather than at the flakes, and occasionally takes a small sample where psoriasis is a possibility. [1] That is a fifteen-minute answer to a question people carry for years.
What it takes to find out which of the four you have. Parting the hair and looking at the skin underneath separates a condition that needs a prescription from a scalp that needs clearing and a better routine.
What your flakes are telling you
You can narrow this down yourself before you come in, and it makes the appointment faster. Look at the scale rather than the amount of it, in good light, on a day you have not washed.
| What you see | What it usually points to | What it needs |
|---|---|---|
| Fine, dusty, white flakes, mild itch | Dryness, or very mild seborrheic dermatitis | The right routine, and often a medicated shampoo |
| Greasy, yellowish scale, oily scalp, itch that can be intense | Seborrheic dermatitis [2] | Prescription treatment, then maintenance |
| Thick, silvery, well-defined patches you can feel the edge of | Scalp psoriasis | A different prescription entirely |
| A film or grit that comes off when you scratch, little redness | Product and oil buildup | Clearing, then a routine that stops it returning |
| Redness spreading onto the face, eyebrows or behind the ears | Seborrheic dermatitis beyond the scalp [2] | Treatment across all the affected areas at once |
| Scaly patches with hair loss in the same spot | Worth an appointment sooner | Examination, because a few scalp conditions do affect hair |
None of this is a diagnosis, and two of the rows genuinely can look alike under hair. It is a head start, and bringing what you have noticed to the appointment is genuinely useful.
Where it shows up
| Area | What happens there |
|---|---|
| Scalp | Flaking, itching and oiliness, and the place it is felt first and seen last. |
| Hairline and behind the ears | Where scale often spreads, and where people first notice redness. |
| Eyebrows and the sides of the nose | Oily areas that seborrheic dermatitis favors as much as the scalp. [2] |
| Beard area | The same condition, in the same kind of skin, treated the same way. |
| Chest and skin folds | Other oily areas the same condition can appear in. [2] |
Always have had a great experience here.
The Coastal difference
Your stylist sees hair. We see skin.
A stylist will notice your scalp is flaking. A board-certified dermatologist can tell you whether that flaking is seborrheic dermatitis, psoriasis, a reaction to something you are putting on it, or simply dryness. Those four have four different answers, and only one of them comes off a shelf.
That is the whole value of having your scalp looked at here. Prescriptions and clearing treatments sit under one roof, so the plan does not wait for a second appointment somewhere else. It is also why scalp complaints so often turn out to be the visible corner of something else, which is easier to catch when the person looking has spent a career looking at skin.
If your scalp needs medicine, it can be prescribed at that appointment rather than after another three months of shampoos. Clearing and the right routine can start the same day.
When to see a dermatologist
Worth booking an appointment when:
- The scale is thick, sticky or silvery rather than fine and dusty
- Redness runs past your hairline, into your eyebrows or beside your nose
- Your scalp is sore, tender or burning rather than simply itchy
- There are scaly patches with hair loss in the same spot
- You have worked through several shampoos without a lasting change
- Something is bleeding, crusting or not healing, which matters because a scalp takes a lot of sun and hair hides it
Also worth knowing:
- Come on a day you have not washed your hair, so the scale can be seen
- Bring the shampoos and products you have been using, or photograph the labels
- Tell us how long it has been going on and what has helped, even briefly
If you are unsure whether it is worth an appointment, it is. Most scalp conditions are straightforward once they are identified, and identifying them is the part that needs somebody looking.
What treatment looks like
Most scalp conditions are controlled rather than cured, and that is a better outcome than it sounds: a clear, comfortable scalp that stays that way with a small amount of upkeep. The pattern is straightforward: treatment to clear the rash and scale first, then a maintenance step such as a medicated shampoo once a week to keep flare-ups away. [1]
Once you have a diagnosis, do
- Use the treatment you are given for as long as you are told, including after it looks better
- Keep the maintenance step going, because that is what prevents the next flare [1]
- Wash on the schedule that suits your scalp rather than the one that feels productive
- Wear sun protection on any thinning or exposed areas of scalp [3]
Once you have a diagnosis, don’t
- Switch shampoos every couple of weeks looking for the one that works
- Scratch or pick at scale, which keeps the cycle going
- Assume a flare means the treatment failed, since flares are part of the pattern
- Leave a new, bleeding or non-healing spot on your scalp unexamined
Tell us if the plan is not working after a fair run at it. There is usually another option, and the second choice often suits better than the first.
Treatments we offer
Once we know which of the four you have, the plan is straightforward. Pick a treatment to see how it works.
What treatment costs
A scalp examination is medical care rather than a cosmetic service and is handled differently from the aesthetic treatments on this site. Our office will go through what applies to you when you book.
Where the answer turns out to be a clearing treatment and a better routine rather than a prescription, that is quoted like any other treatment and you will know the cost before anything is booked.
How it is diagnosed
By examination. Your hair is parted and the skin underneath is looked at
Appointment length
15 to 30 minutes, usually enough to reach an answer
How common
Seborrheic dermatitis is one of the most common skin conditions there is [1]
What to expect
Most scalp conditions are controlled well and kept that way [1]
Scalp health frequently asked questions
The realistic and entirely good outcome for most scalp conditions: cleared, then kept clear with a small maintenance step. That is the recognized pattern. [1]
Offered at
Ready to get an answer? Request an appointment
Fill out the form below, book online in Santa Maria (opens online scheduler), or give us a call. Cosmetic and aesthetic appointments need no referral. For medical dermatology, we are accepting new patients by referral from your primary care physician; send the referral across and then use the same form.
Sources and medical review
1. American Academy of Dermatology Association. “Seborrheic dermatitis: Diagnosis and treatment.” Describes diagnosis by examination with a skin biopsy where another condition such as psoriasis is suspected, notes that having both conditions together “is often called sebopsoriasis,” lists medicated shampoos, topical treatments including ketoconazole and roflumilast foam, corticosteroids and oral antifungals, and describes ongoing management in which patients “often continue to use dandruff shampoo once a week” to prevent flare-ups. https://www.aad.org/public/diseases/a-z/seborrheic-dermatitis-treatment · Medical Organization
2. American Academy of Dermatology Association. “Seborrheic dermatitis: Signs and symptoms.” States that the rash “can develop on any area of the body except the palms and soles,” commonly affecting the scalp, face, ears, chest and skin folds; that it “can be dry, have greasy scales, or both”; that the itch “is usually mild, but it can be intense, especially on the scalp”; and that on deeper skin tones the rash “tends to look pink, slightly purple, or lighter than your natural skin tone” while on lighter skin it “is usually red and raised.” https://www.aad.org/public/diseases/a-z/seborrheic-dermatitis-symptoms · Medical Organization
3. American Academy of Dermatology Association. “How to select a sunscreen.” Broad spectrum, SPF 30 or higher, water resistant. https://www.aad.org/public/everyday-care/sun-protection/shade-clothing-sunscreen/how-to-select-sunscreen · Medical Organization
Content on this page is for educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Scalp conditions are diagnosed by examination and several of them look alike under hair. Most are controlled rather than cured, and flares can recur. Any spot on the scalp that is bleeding, crusting or not healing should be examined. Individual results may vary.