Dandruff and psoriasis of the scalp might look similar but the symptoms may be different.
Although psoriasis of the scalp and dandruff are often confused, they do have different symptoms.
Dandruff is a common scalp condition that causes small pieces of dry skin to flake from the scalp. These flakes can be noticeable and embarrassing if they fall from the scalp to the shoulders, but the condition is not harmful or contagious.
Psoriasis can affect any area of the scalp and will typically appear as thick, inflamed, reddish patches. Scalp psoriasis can be very itchy and the skin can become so dry that it cracks and bleeds.
Other conditions that can cause a flaky scalp include seborrheic dermatitis, which is linked to an overgrowth of yeast on the skin. It can cause the scalp to become itchy, scaly, and red.
Some cosmetic products may cause allergic contact dermatitis on the scalp, which can also display as flaking skin.
"Cradle cap," a type of seborrheic dermatitis, is a kind of yellow, greasy, scaly dandruff that often affects babies in their first 2 months. Symptoms usually only last for a few weeks or months, and gentle washing with baby shampoo can help to prevent a build-up of scales on the baby's head.
Psoriasis has some specific causes, whereas less is known about what causes dandruff.
About half of all people with psoriasis will get symptoms on their scalp. Scalp psoriasis has the same underlying cause as other forms of psoriasis.
It develops when a person's immune system instructs the skin cells to grow too quickly. This causes skin cells to build up on the surface of the skin.
Stress, cold, and dry air can all trigger flare-ups of scalp psoriasis.
Psoriasis is slightly more common in white Americans than African-Americans, and men and women are equally as likely to get psoriasis.
Psoriasis usually develops in people between the ages of 15 and 35, though it can develop at any age. Very rarely, psoriasis may develop in infants.
Dandruff is a common disorder that affects about half of all people at some point in their lives.
There do not appear to be any significant differences in the way dandruff affects men and women and people of different ethnicities.
Some people believe that dandruff is a result of poor hygiene, but this is not true.
Symptoms of dandruff seem to get worse in winter. However, scientists do not yet completely understand the root causes of dandruff.
There are a number of treatment options available for both scalp psoriasis and for dandruff.
Treatment: Scalp psoriasis
A doctor or dermatologist may recommended different treatments for scalp psoriasis such as topical or light treatments.
A doctor that specializes in skin conditions (a dermatologist) can recommend treatments for scalp psoriasis.
Treatments may include:
- medicines that are applied to the scalp
- medicated shampoo
- light treatments
- biologic medicines
Severe cases of scalp psoriasis may require topical treatments, such as:
- anthralin (Dritho-Scalp)
- calcipotriene (Dovonex)
- calcipotriene and betamethasone dipropionate (Taclonex)
- tazarotene (Tazorac)
Other medications that a doctor may prescribe include:
- methotrexate (Trexall)
- cyclosporine (Gengraf, Neoral, SandIMMUNE)
- acitretin (Soriatene)
Moderate to severe psoriasis can be treated with biological medications, such as:
- certolizumab pegol (Cimzia)
- etanercept (Enbrel)
- adalimumab (Humira)
- infliximab (Remicade)
- golimumab (Simponi)
People with more severe scalp psoriasis may need to try several treatments before they find the one that works for them.
Also, after repeated use, a person's psoriasis may become less responsive to the medication. If this happens, treatments may be combined and rotated.
Shampoos are a common over-the-counter treatment for dandruff however if symptoms have not improved after a month then a doctor should be consulted.
There are many different shampoos that are available over the counter to treat dandruff.
Some of these shampoos have slightly different instructions on how long people should lather or rinse. For maximum effect, it is important to follow the label instructions closely.
People should try using other shampoos with different active ingredients if their initial choice is not effective. Active ingredients include:
- zinc pyrithione
- salicylic acid
- selenium sulfide
- coal tar
If a person's symptoms improve, then they may be able to use the shampoo less often. However, if they stop using the shampoo completely, the dandruff will probably come back.
If someone has tried anti-dandruff shampoos for more than a month and their symptoms have not improved, then they should see a doctor.
There are a number of ways that people who have scalp psoriasis or dandruff can care for their scalp. Certain steps can help to manage each condition and provide some relief from symptoms.
Scalp-care for psoriasis
If someone has psoriasis, they should try not to scratch their scalp. This can be difficult because the itching can be very intense. It is wise for people to try not to pick at the build-up of scale, either.
The scalp should be shampooed gently, as rubbing or scrubbing the scalp can make psoriasis worse.
Psoriasis can be made worse by stress, so finding ways to unwind can also help people with this condition.
Scalp-care for dandruff
If a person has dandruff, they should be careful when using a dandruff shampoo that uses coal tar. This is because these sorts of shampoo can discolor lighter-colored hair.
People who are white or Asian are advised to use normal shampoo daily, and use dandruff shampoo twice a week. African-American people are advised to shampoo just once a week using a dandruff shampoo.