Dandruff is the common name for a mild form of seborrheic dermatitis of unknown cause. It is a natural and harmless scalp condition in which the shedding of dead skin cells occurs at an unusually fast rate. Because of the oily skin often associated with this condition, these cells clump together and flake off as dandruff.
Dandruff is very common. Up to one-third of the U.S. population is affected by this condition. While it is not considered a disease, dandruff is a cosmetic concern for many people.
The following problems tend to exacerbate dandruff:
- cold weather
- dry indoor heating
- stress (physical or emotional)
- food allergies
- nutritional deficiencies (B-complex vitamins or omega-3 fatty acids)
- use of hair spray and gels
- use of hair-coloring chemicals
- use of electric hair curlers or blow dryers
Causes & symptoms
Dandruff is caused by an overgrowth of skin cells that make up the scalp. It is not known what accelerates this cell growth. However, scientists have suggested that dandruff may be a hypersensitive reaction to the proliferation of Pityrosporum ovale, a yeast that occurs naturally on the scalp. Another theory that held for some time linked dandruff to a fungus. A 2002 report said that scientists had identified new fungi of the Malassezia that seem to exist in overabundance on the scalps of those affected with the disease.
Dandruff is easy to diagnose. The condition is characterized by the appearance of white flakes on the hair or on the shoulders and collar. People with oily hair tend to have dandruff more often. Dandruff usually does not require medical treatment. However, if, in addition to dandruff, a person also has greasy scaling on the face, eyebrows and eyelashes and thick, red patches on the body, he or she may have the more severe form of seborrheic dermatitis. This condition may require medical advice and treatment.
Alternative treatments for dandruff include nutritional therapy, herbal therapy and relaxation therapy.
The following nutritional changes may be helpful:
- Identification and avoidance of potential allergenic foods.
- Limited intake of milk and other dairy products, seafoods and fatty treats. These foods tend to exacerbate dandruff.
- Reduction or elimination of animal proteins and eating mostly whole grains, fresh vegetables, beans and fruit.
- Avoiding citrus until dandruff clears.
- Diet supplemented with B-complex vitamins which may alleviate dandruff condition.
- Avoiding excess salt, sugar, and alcohol.
- Taking 1 tablespoon of flaxseed oil per day. Flaxseed oil is rich in omega-3 fatty acids, which may be effective in treating a variety of skin conditions including dandruff.
From a traditional medical approach, dandruff may be the body's way of eliminating excess protein accumulated but not assimilated in the system. It may also be a symptom of liver and kidney imbalances. A more stabilizing diet is needed, reducing highly acidic foods such as tomatoes and certain spices.
Massaging tea tree oil (Melaleuca alternifolia) into the scalp may help prevent or relieve dandruff. This oil can relieve scaling and itching. Ayurvedic treatment also includes various oil therapies, called suehana for the head. Increased exercise can increase circulation and help eliminate fats and oils.
There is no cure for this natural harmless skin condition. Because a greasy scalp is associated with dandruff condition, more frequent hair washing using regular shampoo is usually all that is needed. In more severe cases, medicated shampoo may be necessary.
The two most commonly used anti-dandruff shampoos are selenium sulfide and zinc pyrithione. Both of these are cytostatic agents. Cytostatic drugs slow down the growth and formation of top skin layer on the scalp. To get the best result, one should leave the shampoo on for as long as possible. It is recommended that a person lather the anti-dandruff shampoo at the beginning of the shower, leave it on until the end of the shower, then rinse, lather, and rinse again. As a result of treatment with any of these drugs, dandruff will become less noticeable. Because it can be irritating, shampoo containing selenium sulfide should not be used if the skin is cut or abraded.
Products containing salicylic acid and sulfur are reserved for more severe cases. Salicylic acid loosens the dead skin cells so that they can be sloughed off more easily. Sometimes, antibacterial shampoos are used to reduce bacteria on the scalp.
Recently, antifungal products, such as ketoconazole (Nizoral) shampoos, are available over-the-counter (1% preparation) and by prescription (2% preparation). These shampoos are often prescribed by dermatologists to reduce the growth of P. ovale. These preparations may be helpful if dandruff is not relieved by other shampoo treatments.
The most severe and recalcitrant dandruff conditions may require tar shampoos. These shampoos reduce the growth of top skin cells on the scalp. It is recommended that the shampoo be left on the hair for at least 10 minutes for best results. Coal tar shampoos can be messy and can stain blond or white hair. Coal tar also can be carcinogenic (causing cancer). However, the FDA approves this product because when used as shampoo, because it contacts the scalp for only a short period of time. Still, it is a good idea to use alternative treatments for this relatively harmless condition.
Because anti-dandruff shampoos may lose effectiveness after a while, it may be helpful to rotate between a medicated shampoo and a regular shampoo or try a different type of anti-dandruff shampoo.
While one can not cure dandruff, it can be easily managed. A mild dandruff condition often responds to more frequent hair washes with regular shampoo. More severe conditions may require anti-dandruff preparations.
Preventive measures include regular hair washing, reducing stress, eating healthy foods and increasing humidity inside the house. In addition, excessive use of hair curlers, hair sprays and gels, and frequent hair coloring should be avoided. These tend to irritate the scalp and may worsen dandruff.
"Dandruff." In The Medical Advisor: The Complete Guide to Alternative & Conventional Treatments, home edition. Alexandria, VA: Time-Life, Inc., 1997.
Murray, Michael T. and Joseph E. Pizzorno. "Seborrheic Dermatitis." In Encyclopedia of Natural Medicine. 2nd ed. Roseville, CA: Prima Publishing, 1998.
Johnson, Betty Anne and Julia R. Nunley. "Treatment of Seborrheic Dermatitis." American Family Physician 61 (2000): 2703-2710.
"P&G Scientists Pinpoint Cause of Dandruff" Health &Medicine Week (August 12, 2002). 11.
Snyder, Karyn. "Is OTC Dandruff Shampoo As Effective As Rx?" Drug Topics Archive (September 16, 1996). http://www.pdr.net.
American Academy of Dermatology. P.O. Box 4014, Schaumburg, IL 60168. (888) 462-DERM. Fax: (847) 330-8907. http://www.aad.org.
"Seborrheic Dermatitis." The Merck Manual of Diagnosis and Therapy. http://www.merck.com/pubs/manual/section101chapter111/111d.htm.
Sorgen, Carol. "Go Hug a Tree: Tea Tree Oil Treats Skin Conditions." CBSHealthWatch. http://cbs.medscape.com.
Teresa G. Odle