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Genetic Evidence for the Cause of Dandruff Behind Fungus

The skin cells of the scalp that usually are shed without being obvious are more prone to stick together into larger clumps. The condition that is commonly called dandruff has several causes, including psoriasis, eczema, and, the most common, seborrheic dermatitis.

A variety of insults changes the ecology of the skin and can result in dandruff. If the cause for the hair loss can be found and corrected, the dandruff will go away by itself once the hair coat returns to normal. In the past, dandruff has been blamed on dry skin, oily skin, washing the hair too often or not enough, on diet, stress or simply a lack of personal hygiene. “Dandruff on the collar” is shorthand for a man careless of his personal appearance.

Tinea capitis is a contagious fungal condition often characterized by severe itching, dandruff and bald patches. Everyone's had itchy scalp or dandruff at some time or another. Although dandruff isn't contagious and is rarely serious, it can be embarrassing and surprisingly persistent. Dandruff from people and animals along with bits of pollen and leaf fragments make up a significant portion of dusty stuff in the atmosphere but have been ignored by climate modelers, according to a German research project cited in the Environment news network.

Seborrheic dermatitis is a disease that causes flaking of the skin. It usually affects the scalp. In adolescents and adults, it is commonly called "dandruff." In babies, it is known as "cradle cap. "Seborrheic dermatitis involving the seborrheic (oily) areas such as the scalp, eyebrows, nasolabial folds, ears, presternal area and central back. Presentation may vary from simple dry scale (dandruff) to greasy scale with erythema, papules and pustules, resembling acne.It can also affect the skin on other parts of the body, such as the face and chest, and the creases of the arms, legs and groin.

Everyone has bacteria on the surface of their skin, but in some people, bacteria thrive in the skin at the base of the eyelashes. Large amounts of bacteria around the eyelashes can cause dandruff-icky scales and particles to form along the lashes and eyelid margins. Then it is called blepharitis.

Seborrheic dermatitis usually causes the skin to look a little greasy and scaly or flaky. Seborrheic dermatitis may accompany rosacea and contribute to the facial erythema, but it is distinguished from rosacea by a prominence of yellowish scaling around the eyebrows and alae nasi, together with troublesome dandruff. Baldness is often blamed on poor circulation to the scalp, vitamin deficiencies and dandruff.

First, researchers grew enough fungus to give dandruff to 10 million people. Next, they sequenced its genes. Then they found out that not only does an icky fungus live on your head and cause dandruff-- but it could be having sex on your head right now.

A team at Procter & Gamble Beauty said they had sequenced the genome of Malassezia globosa, a fungus that grows on the skin of between 50 percent and 90 percent of the population. It causes dandruff and a range of other skin conditions.

Malassezia fungi have been the suspected cause of dandruff for more than a century. Previously referred to as Pityrosporum ovale, Pityrosporum orbiculare, or Malassezia, these fungi are now known to consist of at least seven Malassezia species. Each species has a specific ecological niche, as well as specific biochemical and genetic characteristics. Malassezia yeasts have fastidious culture conditions and exceedingly different growth rates.

Malassezia lives on the scalps of most healthy adults without causing problems. But sometimes it grows out of control, feeding on the oils secreted by your hair follicles and causing irritation that leads to increased cell turnover. The result is a large number of dead skin cells. As the cells fall off, they tend to clump together with oil from your hair and scalp, making them appear white, flaky and all too visible.

Writing in the Proceedings of the National Academy of Sciences, the researchers said their study can shed light on ways to fight not only dandruff, but an infection that can threaten the lives of newborns.” A complete genomic sequencing of a Malassezia genome opens tremendous opportunities for researchers to understand the interactions of fungi and humans," said Thomas Dawson, a scientist at P&G Beauty who led the study.

"It's amazing that the understanding of the genetic make-up of a microscopic organism can have broad implications ranging from human health to agricultural science." The team at P&G Beauty, a subsidiary of the company that makes household products ranging from toilet tissue to shampoo, said M. globosa is capable of excreting more than 50 different enzymes that help digest and break down compounds in the hair and scalp.

"The M. globosa genome sequence also revealed the presence of mating-type genes, providing an indication that Malassezia may be capable of sex," they wrote in their report. Other fungi can reproduce sexually, but this particular type had not been known to, Dawson's team said. This means it could find a way to evade dandruff shampoo.

They said dandruff can affect up to 90 percent of people, and that it has been known for more than 100 years that Malassezia can cause dandruff and eczema. Malassezia fungi also cause systemic infections in newborns, and are related to some fungi that affect plants such as corn. The fungus joins organisms ranging from yeast to rice to human beings that have had their genomes sequenced. Dawson's team said they grew 10 liters (quarts) of the fungus, "equal to the amount of fungus that would be found on the heads of 10 million people," the company said.

Some natural and simple remedy:

Shampoos or lotions containing salicylic acid, coal tar, zinc, resorcin, selenium sulfide, such as Selsun Blue (the shampoo will help prevent the spread of ringworm, but it will not cure it.), ketoconazole, or corticosteroids may be prescribed for severe cases. To apply shampoos, part the hair into small sections, apply to a small area at a time, and massage into the skin. If on face or chest, apply medicated lotion twice per day. When using the anti-dandruff shampoos, it¹s best to leave it on the scalp for five or 10 minutes before rinsing to give the medication time to work; experts advised.
'Methi' seeds are also helpful in fighting dandruff. Soak them overnight, grind the next morning, mix in the juice of neem leaves and apply on the scalp.
Green tea could hold promise as a new treatment for skin disorders such as psoriasis and dandruff, Medical College of Georgia researchers say.
Discontinue the use of hairspray, gel, mousse, and other hairstyling products and stay clean.
Reduce stress and eat a healthy diet, especially with adequate B vitamins, zinc, omega-3 fatty acids, and reduction of sugar- and yeast-containing foods such as bread, beer, and wine.
In half cup of olive oil, put a small amount of camphor warm it lightly and apply to the scalp parting the hair straight and give a circular massage for the entire scalp.
Dandruff sufferers may find that shampoo containing a standardized extract of the plant Solanum chrysotrichum treats their condition as effectively as antifungal shampoo containing the drug ketoconazole, according to a study in Planta Medica.
Early study of aloe lotion suggests effectiveness for treating seborrheic dermatitis when applied to the skin. Further study is needed in this area before a strong recommendation can be made.

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