How does hair grow and should it recycle?
A single hair follicle grows its hair strand over a period of four to six years (the anagen phase). It then rests for two to four months (the telogen phase), after which the “old” hair is pushed out by a new hair shaft. When the new hair grows in, it does so at a rate of approximately one-half inch per month. At any time, 10% of your hair is in the telogen phase and 90% is in the anagen phase.
What causes a change in this hair loss / hair growth process?
If lots of hair begins to fall out throughout the scalp, it's obviously due to a change in the normal hair cycle: either a short anagen phase or an increase in the number of follicles that enter the telogen phase. When the majority of hair follicles “go telogen” it's called telogen effluvium or stress alopecia. A shock to the body's system--which stresses the hair follicles--is often to blame for this change. Two to three months after the stressor hits, up to 70% of hairs can enter the telogen phase causing a massive “fall out.” There are a number of shocks that are known to cause this, including:
- A sudden hormone change (usually a drop in hormone levels)
- After the birth of a baby (delivery of the placenta causes the levels of pregnancy hormones to plummet)
- Discontinuing birth control pills or hormone replacement therapy
- High fever
- Acute trauma (surgery, physical injury or psychological trauma)
- Severe dieting (inadequate protein and iron intake)
- Underactive or overactive thyroid
- Diseases such as diabetes and lupus
- Chemotherapy
- Medications: These include retinoids, blood pressure medication, anti-depressants, certain birth control pills and even NSAID's (including Ibuprofen)
- Burns or radiation therapy
Note: With stress alopecia, the loss over the scalp is general--not patchy--and hair loss on other parts of the body also can occur. You and your doctor may be able to ascertain if your hair loss can be categorized as stress alopecia by running your fingers through your hair and checking to see if the hairs that are shed have clubbed shafts.
Are there other tests that should be done to diagnose telogen effluvium?
Your doctor may want to check your iron and thyroid levels, but in most cases your history is the most important diagnostic factor.
What is the therapy for this type of hair loss?
Mostly reassurance. If the loss is due to a birth, illness, or a self-limited problem, it will stop and will not progress to baldness. New hair shafts will come in, and in a few months the hair loss will diminish. Eventually the hair will grow back and become normal. If the loss was due to a medication, the drug should be stopped. (Note: If it was due to chemotherapy, the course should be completed and hair growth will subsequently return.)
If iron levels are low, iron should be supplemented (after making sure that the cause was not abnormal bleeding, which could be a sign of a serious disorder). If the thyroid level is “off,” this also should be treated.
Can dyes, hair treatment, or certain hairstyles cause hair loss?
Pulling hair tightly into a ponytail and the repeated traction used for hair extensions and tight braiding can cause some hair loss, especially in the temple area. This is called traction alopecia. If not corrected, the hair follicle may be permanently damaged. Chemicals that dye, bleach, straighten or perm the hair can also cause the shaft to break. However, once the chemical insult has stopped, the root portion should grow back.
What if patches of hair are coming out?
This may be due to a condition called alopecia areata. This is thought to be an autoimmune disease in which antibodies attack the hair follicles and hair falls out in small, round patches. In some individuals, this can progress to total loss of hair on the head (alopecia areata totalis), or even complete loss of hair on the head and face (eyebrows, eyelashes), and body (pubic and underarm hair). The latter rare condition is called alopecia areata universalis.
What causes alopecia areata?
White blood cells attack cells in the hair follicles causing hair production to diminish. However, the stem cells that continually supply the follicle with new cells don't seem to be targeted, so the follicle does have a potential to re-grow hair. Although it's not clear why this occurs, there is some thought that it has a genetic basis, making individuals from the same family predisposed to developing the disease. There also may be some sort of trigger that causes the onset of hair loss, perhaps a virus or an environmental contaminant.
There are currently about four million Americans of all ages and ethnic backgrounds who suffer from alopecia areata. One in five individuals with this disease has a family member who also has been diagnosed.
Alopecia areata seems to occur in family members who have had other autoimmune diseases such as diabetes, rheumatoid arthritis, thyroid disease, systemic lupus, pernicious anemia or Addison's disease. Those who develop alopecia areata have been found to have a higher occurrence of thyroid disease, eczema, nasal allergies and asthma.
If I develop this type of hair loss, will it grow back?
In general, there is a very good chance that the hair will grow back, but it can also fall out again. There's no way of predicting the ultimate course. Some individuals lose just a few patches of hair, it grows back, and the condition doesn't recur. Others continue to lose and re-grow hair for years and still others lose all the hair on their head, face and body; rarely this is permanent.
How is this treated?
There are a number of therapies currently being used (when there are multiple therapies, it generally means that no one is going to be absolutely effective). They include:
- Corticoid steroids: These are cortisone type anti-inflammatory drugs that help to suppress the immune system; they can be given as a pill, topical ointment, or an injection directly into the hairless patches on the scalp.
- Minoxidil 5% (known under the brand name of Rogaine): This promotes hair growth in several conditions in which the hair follicles are small and not growing to their full potential. It needs to be used on a daily basis. New hair growth can appear in about 12 weeks; however, if use of the drug stops, the new hair may fall out.
- Anthralin (Psoriatic): This is a tar like substance that is used to treat psoriasis; it changes the immune function in the affected skin . If it does work, new hair growth is seen in eight to twelve weeks. It is often used in combination with other medications.
- Sulfasalazin: This sulfa drug is used to treat autoimmune disorders.
- Topical sensitizers: These, when applied to the scalp, cause an allergic reaction that leads to itching and scaling, but also stimulate the hair follicles and can cause hair growth. Again, results are only seen after long-term use, usually three to twelve months.
- Photo chemotherapy: This too is used for psoriasis. It has helped about half those treated, but requires special equipment and treatment two to three times a week. There are concerns that it could increase risk of skin cancer.
Are there other causes for “patchy hair loss”?
Yes, it can be caused by fungal infections such as ringworm and syphilis.
What about genetic or inherited hair loss?
We all know that men can become bald as they get older. As a matter of fact, inherited or male pattern baldness occurs in 25% of men by age 30 and two-thirds are bald or balding by the time they reach 60. This male pattern baldness usually occurs in the hairline and around the crown. It continues until there is just a ring of hair along the side. The male pattern of balding occurs from the effects of testosterone, after it is converted to the more potent DHT (which is the only form that will attach to receptors on the hair follicle). Men with male pattern balding don't have more testosterone; they simply have an increased conversion of testosterone to DHT in the scalp. (Note: The drug that helps prevent this conversion is called Finasteride. It is only for men and has not been shown to be effective in women. As a matter of fact, there is concern about women being exposed to Finasteride, especially during their reproductive years, since it could cause fetal malformations.)
Women, however, do develop thinner hair as they get older, often accompanied by gradual hair loss. This loss occurs over the top and sides of the head, not on the crown. Once more, it is felt that genetics play a role and that it is far more likely to occur if relatives on either side of the family have experienced balding as they age.
What therapies target this hair thinning and loss?
The drug Minoxidil, which was first developed to treat high blood pressure, was found to have a side effect of thickening hair growth in some of those treated. It's now available over the counter as a lotion applied to the scalp. No one quite knows how it works, but it seems to be effective in about 20% of women who develop diffused hair loss or thinning, especially if they are younger when they begin to lose their hair. The disadvantage is that if daily use is stopped, the new hair will fall out.
There are also surgical techniques for restoring hair. The two main options are:
- Hair transplantation: Hair follicles are taken from elsewhere on the body, or the back of the head where there is more hair, and implanted into the thinning areas. Because women are more likely to have overall loss of hair on their scalp, this technique may be less successful for them than it has been for men.
- Scalp reduction: Devices are inserted in the skin to stretch the area of scalp that still has hair and the bald areas are removed. Flaps of scalp with hair can also be moved around the head. This technique is no longer in wide use and is not recommended.
What about all those so-called wonder products that are advertised on the Internet?
Beware if they say they are going to quickly and easily cure pattern hair loss. They probably won't. You are providing money for the individuals who are using the Internet to promote their product, and there's a good chance the product will not promote your hair growth.