Alopecia Overview

Alopecia is a group of conditions that are characterized by partial or complete hair loss. Depending on the type of alopecia you have, hair loss may occur anywhere on the body. The most common area to lose hair is the head.

Some types of alopecia are common and some are very rare. The most common form of alopecia is called male- or female-pattern baldness, which is genetic. Researchers estimate that half the population will develop this form of alopecia at some point in their life. Other forms of alopecia may be caused by stress, hair damage, an autoimmune reaction, or as a consequence of chemotherapy.

a man using a comb to pull his hair back and show a bald spot

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Types of Alopecia 

There are two different overarching types of alopecia. These types describe whether the hair follicle becomes damaged, preventing hair from regrowing:

Non-Scarring Alopecia

Most forms of alopecia are non-scarring. The hair follicle is left intact and it is possible for hair to regrow. The types of non-scarring alopecia include:

  • Alopecia areata: A condition that causes patchy baldness anywhere on the body
  • Androgenetic alopecia (male- and female-pattern hair loss): A common form of hair loss tied to genetic factors and sex hormones causing the hair to stop growing and start falling out
  • Traction alopecia: Hair falling out due to physical tension, which can be caused by certain hairstyles
  • Telogen effluvium: A temporary form of hair loss that occurs a few months after physical or emotional stress
  • Trichotillomania: A psychiatric condition involving compulsive hair pulling
  • Postpartum alopecia: A form of telogen effluvium that occurs months after childbirth
  • Chemotherapy-induced alopecia (anagen effluvium): Hair loss that occurs as a side effect of cancer treatments

There are many treatment options for non-scarring alopecia to both slow hair loss and promote hair growth.

Scarring Alopecia

This form of alopecia involves damage to the hair follicles. It occurs when the immune system attacks the hair follicles. This can lead to scaly or scarred skin, inflammation, and pain. This type is more difficult to treat, but there are interventions that can help manage the symptoms.

  • Central centrifugal cicatricial alopecia (CCCA): A permanent form of hair loss that commonly occurs in African American women. It leads to circular patches of baldness on the top of the scalp and inflammation.
  • Lichen planopilaris (LPP): This inflammatory scalp disorder leads to band-like patches of hair falling out and a thickening of the outer layer of the skin, causing excessive skin shedding.
  • Frontal fibrosing alopecia (FFA): A form of lichen planopilaris that usually affects post-menopausal women.

Alopecia Symptoms

There are many symptoms of alopecia. Some like hair loss on the scalp are very common. Other symptoms like the loss of eyelashes are less common.

Common symptoms include:

  • A gradual thinning of the hair on your head
  • A growing bald spot
  • A receding hairline
  • A pattern of hair falling out in patches or strips

When the hair loss occurs fast, you may experience these symptoms:

  • A patch or strip of hair falling out in a day or two
  • Hair falling out in clumps when you’re brushing it or showering
  • Most or all of the hair falling out at once

Alopecia may also cause hair loss elsewhere including the eyelashes, eyebrows, facial hair, nose hair, pubic hair, and other body hair.

Other symptoms of alopecia include:

  • Burning or itching on the scalp
  • Burning or stinging before sudden hair loss
  • Redness, swelling, or sores
  • Scaly bald patches
  • Brittle or fragile nails
  • Black or yellow spots on the scalp

What Causes Alopecia?

There are many reasons that someone may experience hair loss. The hair follicles themselves may shrink. Sometimes, the immune system may attack the hair follicles, destroying them. In other cases, the hair can become fragile or it may fall out faster than normal.

Causes of Non-Scarring Alopecia

There are many factors causing non-scarring alopecia. These differ by type:

  • Alopecia areata: A condition caused by an overactive immune system attacking hair follicles. There is a genetic component to this condition, but more research is needed.
  • Androgenetic alopecia (male- and female-pattern hair loss): This form of hair loss is caused by genetic factors as well as an increase in the sex hormone dihydrotestosterone. It shrinks hair follicles and stops hair growth, causing it to fall out. 
  • Traction alopecia: This condition is caused by hairstyles, products, and treatments that put stress on the hair, such as excessive hair washing or blow drying. The hair becomes fragile and prone to breaking. 
  • Telogen effluvium: A temporary form of hair loss that is caused by physical or emotional stress.
  • Trichotillomania: Hair loss is caused by an underlying psychiatric condition that causes compulsive hair pulling. 
  • Postpartum alopecia: A form of telogen effluvium that occurs due to the stress of pregnancy and changes in hormones. 
  • Chemotherapy-induced alopecia (anagen effluvium): Hair loss that occurs as a side effect of cancer treatments that stop cells from growing.

Other potential causes of non-scarring alopecia include:

  • Consuming a low-protein diet
  • Medications, including retinoids, hormonal birth control, beta-blockers, calcium blockers, antidepressants, and non-steroidal anti-inflammatory drugs (NSAIDs)
  • High fever or severe infection
  • Thyroid disease
  • Hormonal changes
  • Age-related hair loss

Causes of Scarring Alopecia

In some cases, the immune system attacks the hair follicles for an unknown reason. This damage prevents hair from growing back. Scientists speculate the following might cause these forms of hair loss: 

  • Central centrifugal cicatricial alopecia (CCCA): Scientists believe it may be caused by low levels of a particular keratin protein or an underlying immune condition.
  • Lichen planopilaris (LPP): Scientists believe this is caused by an overactive immune response to drugs, viruses, infection, or other allergens.
  • Frontal fibrosing alopecia (FFA): A variety of factors may cause FFA, including an overactive immune response, genetics, hormonal changes, or surgeries that affect the face or scalp. However, more research is needed.

How Is Alopecia Diagnosed?

Alopecia is diagnosed by a dermatologist (a medical doctor specializing in conditions of the hair, skin, and nails). In addition to a physical examination and medical history, diagnosing alopecia may require one or more of the following tests:

  • Dermoscopy: A handheld device, a dermatoscope, magnifies scalp features for the dermatologist. Features such as black dots, hair that becomes thinner along the strand, and broken hairs can all be indicators of alopecia.
  • Hair pull test: A dermatologist pulls on a small group of hairs, typically 50 to 60, and counts how many are pulled out. A test is considered positive if more than 10% of the hairs are pulled out. If it is positive in more than one scalp area, it suggests telogen or anagen effluvium. If positive in one region, it may be alopecia areata affecting only one part of the scalp.
  • Wood’s lamp exam: A Wood's lamp is an ultraviolet light that is shone on the scalp to diagnose alopecia caused by infection. When the light hits the scalp, certain bacteria, fungi, or changes in skin pigment cause the scalp color to change under the light or fluorescence.
  • Biopsy: This test is used to differentiate between different forms of scarring alopecia. It involves “punching” out a small 4-millimeter piece of tissue from the scalp, near the receding hairline, for further analysis of the tissue.
  • Blood test: This test helps determine whether hair loss is caused by conditions like thyroid disease or vitamin deficiency. It can also measure factors that influence hair loss including sex hormones and inflammation.

Treatments for Alopecia

There are many treatments available for alopecia. Treatments for non-scarring alopecia help slow hair loss and promote hair regrowth. Other treatments target inflammation and other symptoms when alopecia is caused by the immune system attacking the hair follicles and scalp. 

Drug-Based Treatments

There are many drug treatments for alopecia. Drugs that work to regrow hair or slow hair loss tend to take six months or longer to work. They include:

  • Rogaine (minoxidil): An over-the-counter drug that promotes hair growth. When applied to the scalp once or twice a day it. It may activate cellular pathways that promote growth in hair follicles. It may also increase the blood flow of nutrients to the follicle. 
  • Proscar/Propecia (finasteride): A prescription drug that slows hair loss. It works by stopping the process that converts testosterone to dihydrotestosterone, a sex hormone linked to hair loss.
  • Aldactone (spironolactone): A drug prescribed off-label to slow hair loss in women. It works by slowing the production of sex hormones that contribute to hair loss.
  • Corticosteroids like Adcortyl (triamcinolone acetonide): These drugs are prescribed to slow inflammation. They are applied directly to or injected into the scalp. This stops the immune system from attacking the hair follicles. 
  • Immunotherapy: A drug that is rubbed into the scalp weekly that helps regrow hair. The immunosuppressant has a strong effect on the immune system, preventing allergic reactions that attack the hair follicles.

Off-Label Use

A doctor can sometimes prescribe medication “off-label.” This means the drug has not been FDA-approved to treat your condition. In most cases, the drug’s off-label use is common in clinical practice and may be supported by documented case studies and research.

Non-Drug Treatments

There are other treatments that involve surgery, cosmetic procedures, or hair loss concealers. These include:

  • Red light therapy: This is a device that shines red light onto the scalp to promote hair growth. More studies are needed to confirm whether red light therapy works. 
  • Microneedling: This is a device with hundreds of small needles used to massage the scalp. Some preliminary studies have fought this treatment to be effective, but more studies are needed to confirm these findings.  
  • Platelet-rich plasma injections: This treatment involves isolating white blood cells called platelets from your blood and reinjecting them into the scalp. Early studies suggest this treatment may be helpful though more research is needed.
  • Wigs: These are immediate, temporary cosmetic items that can cover hair loss on the head.
  • Concealers: These are over-the-counter sprays or powders that can temporarily hide hair loss. 
  • Hair transplant: This is a procedure that implants donor hair—along with the follicles—into bald patches. The implanted hair will then grow from the area it was implanted on.

How to Prevent Alopecia

The most common causes of alopecia are genetic and, therefore, difficult to prevent. However, there are some ways you can reduce the risk of other forms of alopecia caused by hair damage:

  • Switch to a gentle shampoo 
  • Use a moisturizing conditioner
  • Use soft towels, brush hair gently, and stop pulling or twirling your hair
  • Use the blow-dryer only in lower heat settings
  • Do not use damaging hair products and relaxers
  • Stop smoking, a behavior that may be linked to hair loss
  • Avoid processed foods and low-protein diets, which can cause hair loss

Comorbid Conditions

There are multiple conditions that are comorbid (meaning they can co-occur) with alopecia areata. You are at least two times more likely to have these conditions if you already have this form of alopecia. Many of these are autoimmune conditions (conditions characterized by the immune system mistaking healthy cells for harmful ones and attacking them), including:

  • Eczema and other skin conditions: An inflammatory skin condition that involves the immune system attacking the body, similar to alopecia areata
  • Thyroid disease: An autoimmune condition where the immune system attacks the thyroid
  • Lupus erythematosus: An autoimmune disease where the immune system attacks many different organs
  • Metabolic syndrome: A group of conditions involving inflammation that increases the risk of developing a heart attack, stroke, and type 2 diabetes

Other comorbid conditions include:

  • Vitamin D deficiency: Vitamin D helps hair follicles regulate growth and shedding. 
  • Ovarian cysts: These are fluid-filled growths that develop on the ovary. They may increase the production of sex hormones that lead to hair loss.
  • Anemia: It is unclear why low blood iron levels are linked with alopecia areata.
  • Mental health conditions: Conditions like depression and anxiety may involve abnormal brain inflammation. This may link it to alopecia areata.
  • Tinea capitis (ringworm of the scalp): This is a fungal infection that can cause hair loss, often occurring in children.

Living With Alopecia

Most people who get alopecia live healthy lives. Some tips for day-to-day hair care and management of symptoms include:

  • Wear hats and scarves in winter: The places where hair is lost become more sensitive to cold weather.
  • Consider false eyelashes or stick-on brows: If alopecia affects your eyebrows or eyelashes, your eyes lose a layer of protection. False eyelashes or eyebrows can help protect your eyes.
  • Connect with a therapist or an organization that supports people with your condition: It may help to talk to someone who understands the unique challenges of living with alopecia.
  • Find meaningful ways to express yourself: Some people with alopecia feel a loss of identity over losing their hair. Finding a way to express yourself and your style can help you feel more like, well, you.
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Sources
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