Hair Loss
The causes of hair loss can be broken into roughly six categories: effluviums (hair loss due to emotional of physiological stress), alopecia areata (an autoimmune process), scarring alopecias (an inflammatory condition of the scalp), infectious causes, physical causes (e.g. too much tension placed on hair), and genetic causes (male and female pattern hair loss).
In any year, about 35 million men and 21 million women are experiencing hair loss.
85% of men by age 50, and 45% of women by age 80.
Mostly psychological, but can lead to increased sun-related skin cancers on the scalp.
Symptoms
What are the main types of hair loss and how do they present?
The most common type of hair loss is androgenetic alopecia, also known as male-or-female pattern baldness. It is genetically predetermined, and is the result of hormones—called androgens—acting on hair follicles and progressively shortening their life cycle.
In men, androgenetic alopecia is recognized as a progressively receding hairline and the loss of hair at the crown. It typically affects half of men over 50 years old, but can start as early as adolescence. In women, it is characterized by a more generalized thinning on the top of the head that only rarely leads to complete baldness. These cases can also begin early, though they more commonly presents after menopause.
Telogen effluvium, the second most common type of hair loss, affects people who undergo some type of significant physical, metabolic, or emotional stress. Many women, for example, experience this after giving birth. Hair abruptly shift from the anagen (growth) into the telogen (resting) phase and falls out. Surgery, severe injury, chronic illness, or rapid weight loss due to diet can also trigger telogen effluvium.
Treatment (Androgenetic Alopecia)
When do you consider treatment?
This is an individual decision, but beginning earlier leads to better cosmetic results. Androgenetic hair loss involves a gradual shortening of the hair growth cycle along with a shrinkage (miniaturization) of the primary hair follicle, which eventually becomes detached from associated structures within the skin. Once this occurs, hair loss is currently not reversible. But studies have shown that men who started finasteride maintained more hair after five years than those who started a year later.
How do approaches to hair loss treatment differ for men and women (and why)?
The underlying cause of both female and male androgenetic alopecia is similar but, due to differing numbers of hormone receptors and levels of androgens, the treatments can be slightly different.
For example, some women who have elevated levels of androgenic hormones (testosterone, androstenedione, etc.) can take a medication—called spironolactone—to lower them. This testosterone-lowering approach would not be appropriate for men.
Men, on the other hand, respond well to a medication called finasteride (Propecia), which decreases the conversion of testosterone to dihydrotestosterone (DHT) in the scalp.
Both men and women respond to topical minoxidil (a common brand name is Rogaine), a non-androgenic treatment that lengthens the hair growth cycle through a not-yet-fully-understood mechanism.
What are the most common treatment options?
Topical minoxidil 5% and finasteride 1 mg have been FDA-approved for androgenetic hair loss in men. For women, the FDA has only approved minoxidil 2%. Both of these medications need to be taken indefinitely to prevent continued hair loss.
In addition, some relatively new approaches offer the possibility of maintaining or regrowing hair without having to use medication. Low level laser treatment (LLLT) consists of a device that emits a low-power, coherent, and monochromatic red light that can stimulate hair growth on the scalp. Platelet rich plasma (PRP) involves multiple injections of a patient’s own platelets into their scalp over the course of a few months.
If the patient has areas without active hair follicles, they can also undergo surgical hair transplantation. The newest such method is called follicle unit extraction (FUE). With this method, the surgeon removes individual follicles from the back of the scalp and implants them in the desired area.
Of the two medicines, how well does treatment work?
Minoxidil topical, available over-the-counter as a solution or foam, is applied to the affected area twice daily. The mechanism of action is not completely understood, but it involves increasing blood supply to the hair follicle, which lengthens the growth phase and retards hair loss. Studies show that about half of men see improved hair density from the 5% solution. Unfortunately, the overall miniaturization of the hair follicle continues, albeit at a slower rate.
Finasteride, a prescription medication taken by mouth, works by inhibiting 5 alpha reductase, an enzyme that turns testosterone into dehyrotestosterone (DHT) in the skin. By binding to receptors on the hair follicle, DHT causes a progressively shortened growth phase. By lowering the amount of DHT in the body, finasteride decreases the signalling pathway that leads to the shorter hair lifespan.
Do they work equally well for all people?
While results vary, in general 80% of men taking finasteride will see improvement, compared to 50-60% percent of men taking topical minoxidil. The combination of both has been shownto be more effective than either one by itself. Most women also see an increase in hair density and weight using minoxidil.
What are the downsides?
Minoxidil is generally well-tolerated, but can cause local itching, redness, and flaking in some people. In most cases, the reaction is due to propylene glycol—an ingredient found in the solution—rather than a reaction to the minoxidil itself.
Finasteride is also usually well-tolerated, but about 5% of men experience side effects that include loss of libido, erectile dysfunction, and (to a lesser extent) breast enlargement and worsening of depression and anxiety. These side effects resolve when the medication is discontinued, though there are isolated reports of continued sexual side effects for months or years.
Other Considerations
Who should not take hair loss medication?
Men who have established sexual dysfunction, depression, or anxiety should understand that finasteride could worsen their symptoms. The Prostate Cancer Prevention Study, a 25-year study of finasteride and its effect on prostate cancer, recently concluded that there was “no increased risk of prostate cancer death in men who took finasteride compared with men who did not.”
Is it purely genetic, or are there other factors that influence people’s likelihood and/or progression of hair loss?
Genetics play a very important role in androgenetic alopecia, but other factors may also have an influence. Inflammation, for example, may contribute to follicle scarring and thereby to the irreversibility of hair loss.
In one study, ketoconazole, an antifungal with anti-inflammatory properties, was combined with finasteride or minoxidil. Researchers found that the combination led to more hair growth than either finasteride or minoxidil alone. Since this type of hair loss is not yet fully understood, other approaches to halt or retard hair loss are constantly being studied.
Lifestyle Approaches
Are there any non-pharmaceutical or lifestyle approaches that make a difference?
It’s essential to keep the scalp healthy in order to create the best environment for hair growth. Scalp conditions such as eczema, psoriasis, folliculitis, or any other form of inflammation can negatively influence hair growth and should be addressed prior to, or in conjunction with, any hair loss treatment. Avoidance of hair products that irritate the scalp and excessive sun exposure can improve any hair restoration approach.
Low level light therapy is a relatively new approach for androgenetic hair loss. Multiple studies have shown this to increase hair count and density in both men and women with no known side effects. Care must be taken, however, in choosing the correct device; some may be more effective than others.
Useful Links
A review of low level light therapy for hair loss (Lasers in Surgery and Medicine)
Connect with our physicians
Jamila Schwartz, MD and Steven Winiarski, DO are both members of the Galileo Clinical Team. Connect with one of our physicians about Hair Loss or any of the many other conditions we treat.