Hair loss, also known as alopecia, is a very common complaint, but it can be caused by a number of different disorders. Hair loss disorders can be the result of inflammatory conditions that may damage the hair follicles, or can be caused by an inherited or acquired abnormality of the hair shaft.
Hair growth begins after hair follicles form. A cycle of growth, transformation, and rest recurs throughout life. There are 100,000 to 150,000 hair follicles on the scalp. Human hair growth is asynchronous, which means the follicles are independent of each other. This is the quality that allows us to maintain healthy hair even as we are experiencing hair loss daily.
The phases of the hair cycle, briefly, include a growth period, a regression, and a resting phase. 90 percent of the hair follicles on the scale are in the growth phase at any time.
When hair loss occurs, it may be classified as a structural hair disorder, a scarring alopecia (hair loss), or a non-scarring alopecia.
Cicatricial alopecia refers to conditions that cause irreversible and permanent hair loss. This type of alopecia is known as “scarring” alopecia because of the damage to the hair follicle. Some types of cicatricial alopecia include lupus (discoid lupus erythematosus) and lichen planopilaris (a variant of lichen planis.) There are a number of different diseases that can cause permanent and irreversible alopecia, including a pustular condition that can develop after trauma or scalp surgery. Infection and radiation treatments are other causes of scarring alopecia.
Nonscarring alopecia is usually associated with milder signs of inflammation, so the hair follicle is not destroyed. These types of hair loss include traction alopecia, which occurs as a result of tight braiding or other hair styles that pull on the hair; pressure-induced alopecia, that sometimes occurs in areas of prolonged pressure on the scalp; and alopecia areata, which is an autoimmune form of hair loss. Male pattern baldness, known as androgenetic alopecia, results from the action of hormones on hair follicles in susceptible men. Women also experience thinning on the front and top of the head, sometimes as they age. Trichotillomania is a disorder characterized by plucking hair and it can result in significant areas of baldness.
Chemotherapy may stop the hair cycle, resulting in significant hair loss that usually resolves after treatment. Stress, whether physical or psychological, can shift a large number of hair follicles into the resting phase, resulting in hair loss. Dietary restriction and some medications can cause this type of hair loss, which is fairly diffuse.
Structural Causes of Hair Loss
Some people have genetic abnormalities that result in brittle or fragile hair, leading to breakage. This gives the appearance of thinning hair. It’s more likely that structural hair loss is acquired, through chemical processing, excessive heat, or even teasing and brushing.
Although it is very important to determine why a patient is experiencing hair loss, there are a few general measures you can take. If you are restricting calories or protein, a well-balanced diet may restore your healthy hair. Chronic iron deficiency is another cause that can easily be correct. Hair loss after childbirth is not uncommon and time will restore your hair.
Your dermatologist will take a detailed medical history to determine if your hair loss is the result of a major illness or surgery, medication, thyroid disorders, or stress. Poisonings from heavy metals are another, admittedly rare, cause of hair loss.
There are a number of tests that your dermatologist can perform to help you determine the cause of your hair loss. Dermoscopy is a magnifying techniques used to visualize the hair shafts and follicles. The hair pull test will determine if you have active hair loss – it’s easily done. If you have another skin condition that is contributing to hair loss, a dermatologist can determine whether or not is can be successfully treated.
If you’re experiencing troubling hair loss, call today to schedule an appointment with our cosmetic dermatologist. We have three convenient locations and our staff can arrange a convenient consultation to answer your questions.