August 2014 -

The Hair Growth Cycle

The Hair Growth Cycle has three main phases: Anagen (growth) phase, Telogen (rest) phase, Catagen (degeneration) phase. Recently there has been an additional process described, called Kenogen. Human hair growth cycle is unlike the animal hair growth cycle as each invidual hair cycles independently of those beside it. However, at any point in time, 90% of hairs are found to be in anagen, roughly 10% in telogen and a miniscule amount in catagen.

hair_growth_phases

Anagen

Anagen is also called the “growing phase”. It is a genetically predetermined time period when the follicle is active. This time period can last from 2-6 years. Each area of the body has a predetermined anagen phase. This is why your chest hairs don’t normally grow as long as those on your head.

Catagen

This is a degenerative process where the dermal papilla (that part of the hair follicle responsible for producing the proteins which will form the hair shaft), will start to degenerate and be destroyed. Typically, hair growth stops and the hair follicle is broken down as the hair shaft detaches from the dermal papilla stem cells. It is typically referred to as the “dying phase” in the hair growth cycle. It usually lasts for a few weeks.

Telogen

This is where the hair then goes into a suspended “resting phase” and the club hair is formed. It usually lasts about 3 months. This hair will be gradually pushed out once the new hair in anagen will grow and force it out. Telogen hairs are easily removed from the scalp. This is why when you comb your hair you will remove some. Even more are removed when you wash your hair simply because of the greater amount of manipulation of the hair during the shampoo process. A normal amount that is shed is 50-150 hairs a day. Naturally shed hairs have a white bulb on them (typical club hair).

The Hair Doc

Dr. Llorenia Muir-Green is a practising dermatologist in Jamaica. She has an avid interest in hair and scalp disorders. She is a member of the Medical Association of Jamaica, Dermatology Association of Jamaica and is an Associate Member of the Caribbean Dermatology Association. She was a recipient of the 2013 Fellowship in Hair and Scalp Disorders at the University of British Columbia.

August’s QOM- What’s the difference between dry scalp and dandruff?

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Hey Doc, need some help. How do u differentiate between dry scalp and dandruff, and what’s the treatment for each? What causes or aggravates them? Pls help.

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A completely dry scalp i.e. where there is no oil and the skin cracked is actually not common. There are persons who have genetic and other unusual skin disorders where all of their skin including their scalp is dry. What people often refer to as “dry scalp” is actually dandruff. A flaky scalp does not necessarily mean it is dry. There are also other conditions that can result in a flaky scalp: psoriasis, discoid lupus and other scarring type hair loss.

For most persons they are experiencing seborrhoeic dermatitis which most often refer to as dandruff. Seborrhoeic dermatitis is caused by inflammation of the scalp caused by a fungus that lives on the scalp that feeds on the sebum that our scalp hairs produce. The scalp produces a lot of sebum even more than the face. Your hair type which is excessively curly does not make you be aware of it. For other races with straighter hair it is quite obvious how oily their hair can get. You actually do not need to oil the scalp ever.

The number one thing to alleviate dandruff is to wash your hair often. Do not go a week without washing your hair. You will see a difference in how your scalp reacts. Antifungal shampoos used directly on the scalp can be helpful. Ketoconazole, Selenium sulfide, Zinc Pyrithione II, and Tea tree oil containing shampoos are helpful. Leave them on for ten minutes. Rinse then wash your hair with the regular shampoo afterwards.

About

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ATHD Investigates: Biotin

Biotin is the most talked about hair growth related vitamin on the internet. It has received so much hype that you have to ask yourself, is it really worth it? Especially for what some brands are asking you to pay for it!

biotin

Biotin is a member of the B Vitamins. It is a coenzyme i.e. it is needed for the functioning of several enzymes in the body and in general it helps maintain healthy skin, nerves and just the operation of cells in the body*. Biotin was found to be necessary for the development of a good fur or hair coat for animals. Its deficiency in humans is extremely rare and results in a characteristic syndrome of:

1. Hair loss

2. Skin rash (namely around eyes, mouth and genitals)

3. Numbness and tingling in the hands and feet

4. Depression

It is abundantly available to humans in several ways. It is readily available in plenty of foods we eat. Foods with high sources of biotin include nuts (peanut and almond), wheat germ, whole-grain cereals, whole wheat bread, poultry, eggs, dairy products and salmon. Biotin that is absorbed into the body is actually recycled several times before it is expelled through urine or faeces. Lastly, gut bacteria actually produce a lot of biotin. So with all these sources, it is pretty hard to be biotin deficient unless you consume a lot of raw egg whites which contains a protein that binds readily to biotin thus depleting it from the body.

There are persons who may need vitamin supplementation. These include pregnant and breastfeeding women and athletes. Supplementation has been touted to be useful in persons who smoke, have diabetes or have some other nerve disorder. Biotin is useful in persons with nail diseases that make their nails quite brittle. Supplements have also been found to help strengthen hair not necessarily make it grow faster. It is worth taking if you find that your nails and hair break or split very easily. It, however, cannot make persons with Male or Female Pattern Hair Loss regrow hair as their hair loss is from something totally different. It is also least likely to be culprit for Telogen Effluvium (excessive hair shedding). The most common cause for Telogen Effluvium in women is Iron deficiency.

Typical recommended doses for supplementation are 30-35 mcg for women. This is far lower than the mega doses seen in some of the hair vitamins on the market. Though higher doses are not necessarily bad, the exact toxic dose is not known. And yes there are times when too much of a vitamin is not a good thing.

So is it worth taking? Yes, only if you want stronger hair which will make it easier for you to retain length.

*An enzyme is a protein responsible for speeding up reactions in the body