Dandruff

What Is Dandruff? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Holly Pevzner
By Medically Reviewed by 
Reviewed:
Medically Reviewed

Dandruff occurs, essentially, when small bits of dry skin are shed from the scalp. You might spy these flakes in your hair or on your shoulders. Dandruff may make your scalp itchy, too. It’s a common problem, but it isn’t as simple as it seems. Dandruff is actually quite tricky to define because it overlaps with seborrheic dermatitis (a chronic form of eczema) and other skin conditions that lead to a scaly scalp. Here’s what you need to know.

Signs and Symptoms of Dandruff

The big tip-off that an individual may have dandruff are the telltale patches of white flakes on the scalp, made up of dead skin, that come loose in your hair. According to the Merck Manual, other signs include:

  • At times, the scalp can be itchy
  • Greasy or dry scales on the scalp
  • Yellowish to reddish scaly raised bumps along the hairline (in severe cases)

Common Questions & Answers

How do I stop my dandruff?
Try washing daily with a gentle shampoo, an over-the-counter or prescription dandruff shampoo, and cutting back on styling products. Medicated shampoos might not be useful for healthy Black hair, however, but if used on the scalp alone they could be helpful.
What causes dandruff?
It’s caused by dry skin, or the buildup of oil. Skin conditions like seborrheic dermatitis, a weakened immune system, and certain neurological disorders, such as Parkinson’s disease, can also cause dandruff.
Is having dandruff healthy?
It’s not usually the sign of a serious medical problem, but if it’s a chronic condition due to something like a skin issue such as seborrheic dermatitis, it requires treatment.
How long can dandruff last?
It can’t be cured, and can be chronic, but in some cases, a change of habit — washing your hair more often, for example — can clear up flakes fairly quickly.
Is dandruff a fungus?
In some cases, it’s caused by yeast, which is a fungus. The yeast can feed on scalp oils, and bodies will mistake this breakdown of oils for an irritant. The scalp then speeds up skin cell renewal, which causes dandruff.

Causes and Risk Factors of Dandruff

Dandruff can happen for a number of reasons.

Seborrheic dermatitis If you have a particularly bad case of dandruff, it’s likely a mild case of seborrheic dermatitis (SD), according to the American Osteopathic College of Dermatology.

SD is a chronic form of eczema that affects areas of the body that secrete the most sebum, or oil, notes the National Eczema Association.

People with oily skin are often more prone to dandruff. The reason: A yeast called Malassezia globosa feeds on oils on the scalp. Some people’s bodies perceive this breakdown of oil as an irritant, so the scalp reacts by upping the speed at which skin cells renew, causing dandruff, notes Amy McMichael, MD, a professor of dermatology and the chair of the department of dermatology at Wake Forest School of Medicine in Winston-Salem, North Carolina. For those without dandruff, it takes a whole month for new skin cells on the scalp to mature, die, and shed. But for those with dandruff, this process occurs in a mere two to seven days, according to a report in the Journal of Medical Chemistry.

Still, it's important to note that while M. globosa has long been thought to be the main risk factor for dandruff, a causal relationship has yet to be firmly established, noted a July 2019 report in the journal Experimental Dermatology.

Contact dermatitis Contact dermatitis is skin irritation caused by either an allergen or an irritant, resulting in an itchy, possibly painful rash. And in the case of dandruff, that reaction is on the scalp. This generally occurs because of hair-care products or dyes, according to the American Academy of Dermatology Association.

Dry skin If cold winter air dries out your skin all over, including your scalp, then dry skin may be the cause of your dandruff. When dry skin causes dandruff, the flakes are usually smaller and less oily than the flakes caused by SD. (In addition, cold and dry climates can worsen SD, according to the Cleveland Clinic.)

Almost anyone can have dandruff, but the following factors can make you more susceptible.

Shampooing habits “For those who are already at risk for dandruff, washing infrequently can worsen the condition,” says Dr. McMichael. Taking extended breaks can lead to a buildup of oil that can lead to dandruff.

Age Dandruff often begins at puberty and peaks around age 20, becoming far less prevalent among folks over 50 years old, according to a review published in the Journal of Clinical and Investigative Dermatology.

Sex Androgen hormones, such as testosterone, stimulate activity in the sebaceous glands. More oil means an increased chance of an inflammatory reaction and dandruff. Men are more frequently affected by dandruff than women.

Weakened immune system SD is more prevalent in individuals who’ve undergone an organ transplant and those with HIV or AIDS, hepatitis C, or alcoholic pancreatitis. For example, 30 percent to 83 percent of those with HIV report SD.

Neurologic and psychiatric conditions Parkinson's disease, Alzheimer's disease, epilepsy, traumatic brain injury, and spinal cord injury are among the conditions that elevate one's risk of SD, including dandruff.

Those with Parkinson's disease, for example, have an impaired autonomic nervous system that helps to control things like oil gland secretions, which can lead to an overproduction that leads to dandruff, according to the American Parkinson’s Disease Association.

History of other skin disorders Eczema, rosacea, psoriasis, or acne can trigger or worsen seborrheic dermatitis.

Oily skin If you have naturally oily skin, you’re at an elevated risk for seborrheic dermatitis.

Oiling your scalp “Certain oils applied to the scalp can cover the scale, but worsen the flaking and itching response,” notes McMichael.

How Is Dandruff Diagnosed?

A dermatologist can usually diagnose dandruff simply by looking at your scalp. If your dandruff does not respond to treatment, your healthcare provider may opt to perform a skin biopsy in order to rule out other possible issues, notes the Cleveland Clinic.

Duration of Dandruff

Dandruff due to seborrheic dermatitis is a chronic condition that warrants repeated or long-term treatment. As for dandruff that arises from contact dermatitis, dry skin, or shampooing habits, a change of habits should clear up flakes fairly quickly.

Treatment and Medication Options for Dandruff

Dandruff is an often chronic, but treatable, condition.

Gentle over-the-counter shampoo To reduce oil and skin cell buildup, wash hair daily with a gentle shampoo, lightly massaging the scalp to loosen flakes, per the Mayo Clinic.

(See the Black Women and Dandruff section, below, when daily washing isn't recommended.)
OTC dandruff shampoo If gentle shampoo is not helping, try an over-the-counter (OTC) dandruff shampoo.

It’s best to alternate between two or three of these shampoos, notes the American Osteopathic College of Dermatology.

For mild to moderate cases, look for dandruff shampoos that contain the following active ingredients.
  • Selenium sulfide This antifungal slows the death of skin cells. This active ingredient can be found in Head & Shoulders Clinical Strength and Selsun Blue, among other shampoos.
  • Pyrithione zinc This antibacterial and antifungal combo is in Head & Shoulders, DermaZinc, and Jason Dandruff Relief 2 in 1.

  • Salicylic acid Neutrogena T/Sal and Baker's P&S both rely on salicylic acid to slough away flakes and promote healthier skin.

  • Ketoconazole Nizoral A-D is a treatment that contains the antifungal ketoconazole; it can be found both OTC and via prescription

    and can be formulated as a shampoo, gel, or mousse.

  • Tar Tar-based shampoos, like Neutrogena T/Gel, act as both an antibiotic and antifungal. But if you have blond, white, or gray hair, a tar shampoo can cause discoloration. This treatment can also make the scalp extra sensitive to sunlight.

Prescription Dandruff Treatment

If regular and proper use of OTC shampoo, for several weeks, does not alleviate dandruff, ask your dermatologist if you’d benefit from a prescription-strength antifungal shampoo like Loprox or Nizoral, or a topical corticosteroid lotion,

such as Capex or Synalar (fluocinolone topical), Luxiq (betamethasone topical), or Clobex (clobetasol topical).

An alternative to corticosteroids for dandruff treatment is a class of drugs called calcineurin inhibitors. These, like Protopic (tacrolimus topical) and Elidel (pimecrolimus topical), work by helping to suppress the immune response, according to Harvard Health.

Alternative and Complementary Therapies

Tea tree oil Shampoos or topicals that contain 5 percent tea tree oil (an antiseptic, antibiotic, and antifungal) appear to be a safe and effective treatment for dandruff, according to a small randomized study in the Journal of the American Academy of Dermatology.

Healthy fats Increasing your intake of omega-3 fatty acids, like those found in salmon, tuna, and mackerel, will help regulate oil production on the skin, notes Cedars-Sinai.

Additional Approaches

Get some sun. Brief bouts of sunshine can help reduce yeast production on the scalp.

But if you are also using a tar-based dandruff treatment, avoid direct sun exposure, as your scalp is especially sensitive to sunlight.

Cut back on hair products. Styling gels, sprays, pomades, and more can build up on the hair and scalp, increasing oiliness and dandruff.

Prevention of Dandruff

“You can prevent the signs and symptoms of dandruff, but there is no cure for dandruff,” says McMichael. If you’ve got an especially oily scalp, daily shampooing with a gentle cleanser, coupled with a light scalp massage, may help prevent dandruff in certain cases. If you're using an OTC dandruff shampoo, talk to your dermatologist about how often to use it for maintenance and prevention. Finally, increased omega-3 intake, brief exposure to sun, and fewer hair products can help prevent dandruff as well.

Black Women and Dandruff

In a study in the Journal of Clinical and Aesthetic Dermatology, 44 percent of Black women reported a history of seborrheic dermatitis symptoms, such as excessive itching or scaling on their scalp.

Unfortunately, Black women also tend to face some common dandruff-treatment barriers. “Because many Black women do not wash their hair frequently through the week, this can make dandruff worse and treatment challenging,” notes McMichael, who recommends Black women aim to wash at least every two weeks, but once weekly is best. Another barrier: Medicated shampoos tend to be great for the scalp, but not for healthy Black hair, due to hair shaft dryness. “That means that using these shampoos on the scalp alone, not the whole head of hair, is often best,” says McMichael.

Research and Statistics: How Many People Get Dandruff?

Dandruff affects approximately 50 percent of the general adult population worldwide, according to past research.

Dandruff is more prevalent in males than females.

Conditions Related to Dandruff

“Sometimes what you think is dandruff is simply product debris, like hair gel or hair spray,” says McMichael. Other times, it may be one of these conditions.

Cradle cap Technically, seborrheic dermatitis and cradle cap and dandruff are all the same thing. Cradle cap affects infants between two weeks and 12 months old; they develop greasy, scaly, or crusty red or yellow patches on the scalp, according to KidsHealth. (The flaky rash can also appear on the face, diaper area, and other areas of the body.)

Scalp psoriasis About 50 percent of people who have plaque psoriasis experience a flare-up on the scalp at some point. On the scalp, you may have reddish patches, dandruff-like flaking, silvery-white scale, and dryness. Scalp psoriasis is often itchy, with the itch ranging from mild to intense, notes the American Academy of Dermatology Association.

Tinea capitis This highly contagious fungal infection is also called ringworm of the scalp and hair shafts. Symptoms may include itchy, scaly, and bald patches on the head. Tinea capitis is most common in toddlers and school-age children, per the Mayo Clinic.

Resources We Love

Skin of Color Society

This professional dermatologic organization is dedicated to promoting awareness of (and excellence within) the dermatological care of skin of color. SCS offers a Find a Doctor database to help those of Asian, Hispanic or Latino, African, Native American, and Pacific Island descent find local dermatologists who are especially knowledgeable about their skin concerns. Whether you’re struggling to find a dermatologist who can help treat persistent dandruff in Black hair or you’ve got another skin-related issue, SCS’s Find a Doctor database can help.

American Academy of Dermatology

The AAD is the largest dermatology group in the United States and its website is full of resources, tips, and more. Curious how to ease your itchy skin? Check out their Everyday Care section. Craving some insider secrets to tackle your rosacea? Try the AAD’s Diseases and Conditions area. Not sure how to combat your child’s dandruff? Go to the areas dedicated to Parents and Kids.

Editorial Sources and Fact-Checking

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