Both dandruff and psoriasis can cause flakes to appear on the scalp. However, flakes caused by psoriasis may also cause dead skin to build up on the surface of your skin.
Dry, flaky skin on your scalp can be uncomfortable. Those flakes can be caused by dandruff or psoriasis, which are two very different conditions:
- Dandruff (also known as seborrhea) can usually be treated relatively easily and is seldom a serious medical problem.
- Psoriasis, on the other hand, is a chronic condition without a current cure. It can cause a great deal of discomfort.
Dandruff is a condition marked by flakes of dry skin on the scalp. The flakes can often fall from your hair and land on your shoulders.
Dandruff is usually due to the body’s overreaction to the presence of typical yeast on the skin. This inflammation leads to the overproduction of skin cells, leading to flaking. If this is the cause, the flakes are typically small and you may also have dry skin on other parts of your body.
Washing your hair with a harsh shampoo or using a lot of chemicals on your hair can sometimes irritate your scalp and lead to flakes.
A fairly common condition called seborrheic dermatitis is the cause of many dandruff cases. Experts consider it a type of eczema that affects areas of the skin with oil-producing sebaceous glands. It’s characterized by patches of red and oily skin that leave yellowish flakes on the scalp. These flakes are often larger than the dandruff flakes that can arise from dry skin.
Seborrheic dermatitis can also cause flaky, irritated patches elsewhere on your face and body, which may lead you to think you have psoriasis.
In Black people and People of Color, seborrheic dermatitis can appear as:
- hypopigmentation, or lightening of the skin
- curved or petal-like lesions along the hairline
- flaking or hypopigmentation on the scalp in infants
Unlike dandruff, psoriasis is rooted in your immune system. It’s considered an autoimmune disease, which means proteins called autoantibodies mistakenly attack healthy tissue.
This attack causes skin cell production to speed up, creating an unhealthy and abnormal growth of new skin that collects in dry, flaky patches on your body, including the scalp.
Typically, dead skin is shed in tiny, thin fragments from the outermost layer of skin. Neither you nor anyone else can usually tell when you lose dead skin. New, healthy skin cells form beneath the surface of your skin and, in a matter of weeks, rise to the surface to replace the dead skin.
If you have psoriasis, that process speeds up in various spots on your body and there’s no time for the dead skin to go through its natural cycle of shedding. That causes dead skin cells to build up on the surface. This usually occurs on the:
- scalp
- elbows
- knees
- back
Psoriasis can take different forms. Sometimes your skin may look cracked and dry. Other times it may be discolored and dotted with small silvery patches. Psoriasis can appear salmon-colored with silvery-white scales on medium skin tones. Darker skin tones could look violet with gray scales.
Dandruff can often be prevented, while psoriasis can’t.
Dandruff
Dandruff can usually be prevented. Using a dandruff shampoo is often enough to keep dandruff from forming. Keeping your hair clean, in general, and washing your hair at least 2 to 3 times a week is ideal.
Oil and dirt can build up on your scalp and cause your scalp to dry. Brushing your hair away from the scalp also helps keep oil from accumulating on your scalp.
Psoriasis
There’s no way to prevent psoriasis.
According to the National Psoriasis Foundation, it’s less common in children and often appears between the ages of 15 and 35, but it can develop at any age.
The organization notes that in the United States, psoriasis affects 3% of adults — as many as 7.5 million people. Psoriasis can develop in people of all ages and skin colors.
Its prevalence by race and ethnicity is as follows:
- 3.6% of white people
- 1.9% of Black/African American people
- 1.6% of Hispanic people
But these numbers may not tell the entire story as the condition may be disproportionately undertreated and misdiagnosed in People of Color because it isn’t always recognized on darker skin tones.
Treatment exists for both dandruff and psoriasis.
Dandruff
Dandruff can usually be treated with medicated shampoo. It’s also important that you follow the directions of any shampoo you use. Some can be used a couple of times per week, while others can only be used once per week. You may have to switch shampoos too, as one may become less effective over time.
The American Academy of Dermatology Association (AAD) recommends that Black people use dandruff shampoo once per week and that white people and people of Asian descent use dandruff shampoo twice per week.
They also note that shampoo containing coal tar can discolor lighter hair, including blond, white, or gray hair.
Psoriasis
Psoriasis can be treated with topical, oral, and injectable medications. Many of these medications are steroids. They help to make the symptoms somewhat milder.
But there’s no cure for psoriasis.
These may include:
- Disease-modifying antirheumatic drugs (DMARDs): These drugs are given to people with moderate to severe psoriasis.
- Light therapy: Light therapy, which targets psoriasis trouble spots with specially directed ultraviolet (UV) light, can also help treat the symptoms of psoriasis.
- Biologics: Biologics can be used to treat various forms of moderate to severe psoriasis. These injectable drugs work by blocking inflammatory proteins.
Often dandruff can be self-diagnosed at home just by observing flakes on your hair and scalp. If you’re concerned it could be something more, a doctor can help identify it as dandruff or psoriasis.
If the doctor believes it may be psoriasis, they’ll ask you if you’re experiencing other symptoms like joint pain or itchy skin elsewhere on your body.
Joint pain and inflammation may be a symptom of psoriatic arthritis. As many as one in three people with psoriasis may develop psoriatic arthritis.
If your dandruff doesn’t go away or doesn’t get better using antidandruff shampoo, you may want to consult a dermatologist. Prescription dandruff shampoos may have the strength you need to overcome the problem. You may also require a medicated topical.
If all signs point to psoriasis, you may want to be evaluated by a dermatologist. If stiff or swollen joints accompany your psoriasis, you may have psoriatic arthritis. A rheumatologist can treat this condition. A primary care physician should be able to help coordinate your care and your various specialists.
Dandruff and psoriasis can both cause flakes of skin on the scalp. But they’re separate conditions.
Dandruff can occur as the body’s overreaction to yeast on the skin or seborrheic dermatitis, a type of eczema.
Psoriasis is a chronic autoimmune condition. It can cause dead skin to build up on the surface of the skin. It may affect the scalp and may also affect other areas of the body.