Doctor's Notes on Dandruff
Dandruff is a condition that occurs due to peeling, or exfoliation, of the skin of the scalp. This process is completely normal, and dandruff becomes a problem due to cosmetic concerns. Excessive peeling of the skin may contribute to dandruff. The most common cause of excessive scalp peeling is seborrheic dermatitis (seborrhea), and inflammatory condition of the skin thought to be related to a specific fungus type (Malassezia furfur) that lives on the skin.
Signs and symptoms of seborrhea include itching along with reddened skin plaques covered by scales. The red, scaly plaques can also occur on the eyebrows, forehead, in the ear canal, and on the skin between the nose and lips. Slowing of hair growth may be an associated symptom, but seborrhea of the scalp does not cause hair loss.
Dermatologists commonly refer to dandruff as seborrhea or seborrheic dermatitis. The signs and symptoms include:
- White flakes on shoulders of dark clothing
- Itchy scalp
- Scaly facial skin
- Recurrent ear "eczema"
- Facial rash over eyebrows, nose, and ears
- Oily scalp and facial skin with dry flakes
- Eyebrow rash
- Beard rash
- Chest rash with dry flakes and red spots
One of the most common and often the first symptom of dandruff can be white flakes seen on dark clothes. Scalp itching may be another common first symptom. In some, the initial noticeable symptom is simply dry facial skin without any other rashes. Patients may see their physician complaining of dry skin that fails to respond to daily lotions and creams. Often they have used every lotion possible from the drugstore or more expensive department stores. Frequently this is caused by undiagnosed scalp dandruff that is causing problems "downstream" on the face.
Dandruff can be located in areas of the body with hair follicles. It is most typically found on the scalp, ears, face, and middle of the chest. Seborrhea is not seen on the palms and soles where there are no hair follicles.
The exact cause of dandruff is unknown. Possible causes and associations include increased oil production and secretion, and increased numbers of normal skin yeasts.
Bacteria have not been found to cause dandruff. Dandruff is not a fungal infection and is not the same as scalp "ringworm," which is actually a fungal infection called tinea capitis. Dandruff is not contagious.
Dandruff may also be triggered or made worse by poor hygiene and infrequent shampooing and washing. The immune system may also play a role in dandruff. Although mild dandruff is a very common condition in many people with a normal immune system, severe dandruff is more common in people with some chronic illnesses such as Parkinson' s disease or a compromised immune system as in advanced HIV/AIDS.
- Common triggers (factors that may worsen) of dandruff include the following:
- Oily skin
- Oily scalp
- Risk factors for dandruff include the following:
- People with extreme or severe cases of dandruff often also have other chronic health conditions
- Dandruff probably has a small hereditary component making it more common to run in families.
As consumers, we have all seen plenty of advertisements dramatizing the repulsive appearance of these small white flakes on dark hair, a dark blouse, or shirt. Dandruff flakes represent scales from the scalp. The word dandruff probably originates from the combination of dander, which refers to skin scales on animal fur or bird feathers and the word hurf, which originates from a 500-year-old English word for crust. A few particles of dandruff go unnoticed. Too much produces angst. It has been estimated that as much as 50% of the population is troubled by this nuisance.
Ringworm : Test your Medical IQ QuizQuestion
Ringworm is caused by a fungus.See Answer
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.