Tuesday, December 9, 2014

Diseases that Cause Hair Loss : Without a Trace: Non-scarring Alopecia , Diagnosing the disorder , Exploring treatment options , Hair today, gone tomorrow: Telogen effluvium , The fungus among us: Tinea capitis , Thyroid conditions and hair loss , Living with a thyroid condition and hair loss , A Potentially Permanent Change: Scarring Alopecia , Lupus: A Scarring and Non-scarring Disease , May Cause Side Effects: Medications and Hair Loss , Prolonged hair pulling: Traction alopecia and Enduring Hair Loss with Chemotherapy

Diseases that Cause Hair Loss

In This Chapter

  • Differentiating between scarring and non-scarring scalp diseases
  • Understanding how lupus can affect hair
  • Knowing what medications can cause hair loss
  • Exploring other causes of hair loss

 

Although the most common cause of hair loss in adults is pat- tern thinning, it’s not the only cause. A number of medical alopecia, the medical term for hair loss.

conditions can cause Alopecia can occur as a disease in which hair loss is the predominant feature, or it may be a side effect from a disease or treatment of disease, such as alopecia caused by chemotherapy drugs.

Alopecia breaks down into two main categories, non-scarring and scarring. If properly treated, a non-scarring disorder can subside and hair can potentially grow back. With a scarring hair loss disorder, the hair follicles are permanently damaged; the chances of hair regrowth after the disorder is treated are very slight.

This chapter looks at the common medical causes of alopecia and their causes, courses, and cures.

Without a Trace: Non-scarring Alopecia

Non-scarring hair loss disorders are generally reversible, but that doesn’t mean that you shouldn’t take them seriously. Here, we describe some of the most common causes of non-scarring hair loss, their symptoms, and their treatments.

Seeing circular bald spots: Alopecia areata

As if there aren’t already enough difficult-to-pronounce terms in this book, here’s another one: alopecia areata. Also called AA, alopecia areata is an autoimmune disease that causes hair loss (see the sidebar “What’s an autoimmune disease?”). AA is some- times called spot baldness because it causes round spots of hair loss. The disease, which is relatively common, tends to run in families and affects about 1 to 2 percent of the population in the United States. In about 2 percent of patients, the disease changes into a more diffuse form of hair loss, covering wider areas of the scalp.

Alopecia areata occurs when a person’s white blood cells attack and destroy the body’s hair follicles. After hair follicles are attacked, they stop producing hair, causing the distinctive localized bald patches that are the mark of alopecia areata. The hair loss usually occurs over a short period of time.

Severe alopecia areata can take two forms:

  •  Alopecia totalis: All hair on the scalp is lost.
  •  Alopecia universalis: All hair on the scalp is lost, along with hair on the eyebrows, eyelashes, and all other parts of the body.

Less severe alopecia areata can take these forms:

  •  Alopecia areata monolocularis: Baldness occurs in only one place on the scalp.
  •  Alopecia areata barbae: Hair loss occurs in patches in a man’s beard.

AA can occur at any age, with most patients diagnosed between the ages of 15 and 29 and nearly half being under age 20. An equal number of men and women develop AA, and the disease occurs equally in every race.

Diagnosing the disorder

Alopecia areata doesn’t follow a predictable path. Some patients feel burning or itching in the area of balding, but others don’t. Eighty percent of patients have only one bald spot. The bald patches can be round or oval in shape, and expose smooth, bald skin.

The disease normally affects only the scalp, but other body hair also can be affected and aid in diagnosing the condition. Interestingly, if you have fingernail abnormalities such as small pits on the nail plate, you may also have alopecia areata. Atopic dermatitis (an allergic skin condition) and vitiligo, a disease that causes white patches on the skin, are also more common in people with AA.

An important diagnostic clue to alopecia areata is the presence of “exclamation point hairs” on the perimeter of the bald patch. These hairs form as the body attacks the lower portion of the hair follicle, and the damage produces a finely tapered end. As the hair continues to grow, it looks like a tiny spear stuck in the scalp. Eventually this hair will be lost, but its presence is a sign of alopecia areata in its active stage.

Your doctor may gently pull hair along the edge of a bald patch to determine whether you have alopecia areata. Healthy hair doesn’t come out when pulled gently, but hair afflicted with alopecia areata is easily removed.

Exploring treatment options

If you’re diagnosed with alopecia areata, the good news is that in 90 percent of cases, hair grows back on its own and no treatment is needed. The chances of regrowth are best when the condition is localized to just a few places on the scalp and the patient is over age 40. In younger patients, unfortunately, the condition tends to be more severe. If the disease progresses to alopecia totalis or alopecia universalis (refer to the earlier section, “Seeing circular bald spots: Alopecia areata”), no surefire treatment is available.

Options for treatment include:

  •  Steroids: One of the main functions of steroids is to reduce inflammation, but in patients with AA, steroids are used to stop the body’s immune cells from destroying hair follicles. Your doctor may inject steroids directly into your bald patches or may prescribe a topical steroid cream that you can apply to the bald patches at home.

When the disease is too extensive to treat with multiple injections or topical creams, oral steroids are an option. Usually, you only take them for a short period of time because of the many side effects of long-term use, including osteoporosis, very fragile skin, and diabetes.

  •  Minoxidil: This medicine works because hair growth is a side effect of the drug that may directly affect bald spots. You apply it directly to the bald patches. Minoxidil is commonly used to treat pattern baldness, but for unknown reasons it also sometimes helps patients with AA.
  •  Cyclosporine: This potent immunosuppressant specifically inhibits T cells, the immune system cells that attack hair follicles in AA. Cyclosporine is most often given orally. It’s more commonly used to treat other conditions such as psoriasis, and many physicians are hesitant to use it medicine to treat AA because it can cause kidney damage, high blood pressure, and suppress your body’s immune system.
  •  DNCB: This chemical (full name dinitrochioro benzene) rapidly produces skin sensitivity. In some people with severe alopecia areata, continued application of DNCB (enough to produce a continuing rash caused by the activation of white blood cells to boost the local immune function). This caused hair regrowth in some individuals. It doesn’t always work, how- ever. You should take DNCB only under the strict supervision of a doctor who’s experienced with this treatment.

Whats an autoimmune disease?

Three diseases that can cause hair loss — alopecia areata, scleroderma, and lupus

— are autoimmune diseases. But what is an autoimmune disease?

Your body’s immune system serves to protect it from outside invaders, such as harm- ful bacteria and viruses. With an autoimmune disease, your immune system turns on itself and starts attacking components of your body. In other words, your body mistakenly thinks that some of its own cells are foreign, disease-causing cells, and so it attacks and tries to kill or damage those cells. Autoimmune diseases result from a failure of the immune system to distinguish between which cells belong in your body and which cells don’t belong.

The cause of autoimmune diseases remains a mystery. They may have a genetic component because they tend to run in families. They’re also much more common in women than in men, but doctors and researchers continue to hunt for the exact cause.

Hair today, gone tomorrow: Telogen effluvium

Telogen effluvium is a type of non-scarring hair loss characterized by sudden, widespread hair shedding. Normally, people lose 100 to 150 hairs each day, but you can lose more than 400 or more hairs daily with telogen effluvium! This disease can occur at any age and may be more common in women because of hormonal changes in menopause. It occurs equally in different races.

Telogen effluvium occurs when a large number of hair follicles suddenly decide to take a rest at the same time (the telogen phase; see Chapter 2 for more on the hair cycle). Then, three to four months later, this formerly resting hair sheds as new hair begins to take its place.

Why does a large portion of hair suddenly enter the resting phase and bring about an attack of telogen effluvium? Usually a traumatic event causes the condition (see the following list for some examples). Essentially, in times of stress, the body diverts its energies to something other than growing hair. As a result, the hair goes into a resting stage until the traumatic event subsides. The problem is that after the trauma, the hair can’t just start growing again. It first has to be shed, and then you have to wait for new hair to grow in.

Common causes of telogen effluvium include the following:

  • An acute illness accompanied by high fever
  • A chronic illness, such as cancer
  • Hormonal changes brought about by childbirth or stopping birth control
  • Sudden changes in diet, including the conditions anorexia and bulimia
  • Medications, such as those used to treat high blood pressure, cholesterol, and seizures
  • Major surgery and general anesthesia
  • Big life changes such as a divorce, death in the family, or loss of a job

People with telogen effluvium often seek help from a physician because the shedding is so sudden. Doctors often diagnose telogen effluvium with a hair pull test; pulling out significantly more than 10 percent of the hair indicates telogen effluvium in its early stage. The condition can be either acute, lasting less than six months, or chronic, lasting longer than six months. But there’s some good

news for telogen effluvium sufferers: After the hairs fall out, they start growing again, so hair loss from telogen effluvium usually isn’t permanent. Be patient and your hair will grow back.

The fungus among us: Tinea capitis

By far the most common reason for hair loss in children is a fungal infection of the scalp called tinea capitis. This condition is rarely seen in adults. Depending on the severity of the infection, it can appear as a mild case of dandruff; reddened, circular areas of com- plete hair loss on the scalp that show whitish, scaly flakes; or a massive blister that covers the whole scalp. Often the infection is accompanied by swollen lymph nodes under the ear and on the back of the neck.

Outbreaks of tinea capitis aren’t uncommon in schools. Doctors can make a definitive diagnosis by taking a fungal culture of the hair or looking at the hair under a microscope and noting the tiny fungal branches. The infection is treated with oral antifungal medi- cine usually taken for a period of several months.

When the infection is mild and treated early, any lost hair is expected to regrow. When the condition is associated with a lot of inflammation, scarred patches may form that are permanently devoid of hair. In this case, the condition should be viewed as a type of scarring alopecia (see the later section, “Scarring Conditions That Cause Hair Loss”).

Thyroid conditions and hair loss

The thyroid is a small gland that resides on the front of your neck. It controls how your body makes proteins and burns energy; it also regulates your metabolism through production of thyroid hormone. Diseases of the thyroid gland can affect hair growth, which fortunately is non-scarring.

Diseases of the thyroid gland

When the thyroid gland produces either too much or too little thyroid hormone, it can have negative consequences for your hair. Fortunately, the following thyroid gland diseases can be detected with a simple blood test:

  • Hyperthyroidism: When the body produces too much thyroid hormone, you may develop hyperthyroidism. Symptoms of hyperthyroidism include a rapid heartbeat, weight loss, heat intolerance, and nervousness. In addition, your hair becomes extremely thin and sparse.
  •  Hypothyroidism: When the body produces too little thyroid hormone, you may develop hypothyroidism. Symptoms of hypothyroidism include fatigue, cold intolerance, lack of energy, puffiness of the face, and dry skin. In addition, your hair becomes dry, brittle, coarse, and sparse.

The most common cause of hyperthyroidism in the U.S. is Grave’s disease, an autoimmune disease (see the earlier sidebar “What’s an autoimmune disease?”). The most common cause of hypothyroidism in the U.S. is Hashimoto’s thyroiditis, also an autoimmune disease. In developing countries, lack of iodine in the diet is the most common cause of hypothyroidism. However, this cause is rare in the United States because iodine is added to table salt.

How thyroid conditions affect hair growth

Doctors aren’t sure why patients with thyroid disease lose their hair. It could be because the thyroid hormone affects the body’s metabolism, including the hair follicles, and so problems with the hormone cause hair regrowth to slow and hair to become thinner and possibly more brittle. This may result in loss of hair bulk. And if the hair shaft hasn’t fully developed, the ends of the hair may split.

Whether or not the thyroid hormone has a direct effect on the condition of hair and its growth, acute thyroid disease is very stressful. As we explain in the section, “Hair today, gone tomorrow: Telogen effluvium,” earlier in this chapter, stress can be an important factor in developing telogen effluvium, in which hair rapidly falls out after prematurely entering the resting phase of the hair growth cycle.

Medications given to treat thyroid dysfunction also can cause hair loss. For example, hair loss is a potential side effect of propylth- iouracil, the most common medicine used to treat hyperthy- roidism. Synthroid (levothyroxine), the most common drug used to replace thyroid hormone, also may cause hair loss. It’s not known why these medications cause hair loss, but it’s important for patients to be aware of their potential side effects.

Living with a thyroid condition and hair loss

If you suffer from thyroid disease and experience hair loss, you should see two important specialists: the endocrinologist, who can diagnosis and treat your thyroid condition; and the dermatologist, who can figure out the exact cause of your hair loss and determine if it’s related to a thyroid disease. Hair loss can accompany many different conditions, so it’s important to eliminate all other possible causes before assuming that a condition is thyroid related.

If your doctor determines that your hair loss is caused by thyroid dysfunction, be patient with treatment. Proper medical treatment and allowing time for your body to adjust to the new medication increase the likelihood that your hair will regrow. But you may have to wait out an entire hair cycle for this to occur, so it may take up to three years for your hair to return to normal.

Thyroid disease treatments

Patients with hypothyroid conditions (too little thyroid hormone in your body) are usually prescribed a drug called synthroid, which is essentially a replacement of the thyroid hormone. Hypothyroidism can be treated with any of the following:

  • Medical therapy in combination with antithyroid drugs. When a person has too much thyroid hormone (hyperthyroid) they are often prescribed medicine that damages the thyroid gland so that it produces less thyroid hormone. At times, this treatment is overdone, so a person who was hyperthyroid becomes hypothyroid so that they need more thyroid hormone to bring the thyroid hormone to normal levels.
  • The destruction of the thyroid gland in combination with radioactive iodine.
  • Surgery to remove the thyroid.

If these treatments don’t work, your doctor should consider treatments for simultaneously occurring androgenetic alopecia, or ANA (male pattern baldness that has a genetic cause; see Chapter 4 for more information). Thyroid disease may bring out the genetic defects of inherited balding so medicines used to treat ANA include topical minoxidil, spironolactone, and oral Finesteride (males only). Often there’s no single reason for hair loss, and these medicines may help decrease hair loss when used with thyroid replacement therapy.

After you’re diagnosed with thyroid disease and begin treatment, you may find that your hair loss begins to improve. However, if you continue to lose hair several months after your thyroid hormone levels have returned to normal, see your doctor to be sure another medical condition isn’t causing your hair loss.

Other diseases that can cause hair loss

Almost any serious illness can cause temporary hair loss. Some of the most common are:

  • Anemia: The most common type of anemia is due to iron deficiency. Decreased iron intake (seen in strictly vegetarian diets) or increased blood loss (sometimes associated with prolonged periods of heavy menstruation) may cause a drop in your iron level.
  •  Diabetes: Endocrine imbalances, stress, and poor circulation all can lead to hair loss in diabetic patients.
  •  Malnutrition, including anorexia and bulimia: These disorders produce hair loss particularly if there’s a deficiency in zinc or essential fatty acids.
  •  Psoriasis: Treatments used for psoriasis or over-vigorous removal of plaques from the scalp can cause scalp inflammation, which may lead to hair loss. When this occurs, it is almost always from a person ‘picking’ at their hair plaques pulling out hair to produce traction alopecia.

All forms of chronic illness cause a metabolic shift of nutrients to the hair follicles and may bring on telogen effluvium (acute or chronic; refer to the earlier section “Hair today, gone tomorrow: Telogen effluvium” for an explanation). Telogen effluvium may last until the primary disease is resolved.

Accidents cause stress and can precipitate hair loss. In men with known genetic hair loss, stressful events can accelerate the process, which may not be reversible even after recovery. In women, hair loss can occur in a similar manner to acute telogen effluvium and reverses after full recovery from the accident.

A Potentially Permanent Change: Scarring Alopecia

Despite the sound of the name, scarring alopecia, also called cicatricial alopecia, doesn’t always cause visible scars on top of your head; the scarring is usually beneath the scalp, where hair follicles are replaced with scar tissue. If severe, it can cause the surface of the scalp to appear smooth and shiny.

All scarring alopecias have similar microscopic features and show the body’s immune cells attacking the skin and hair follicles. The changes in what we see can be quite similar with the changes of the non-scarring alopecias. Doctors categorize these conditions based upon the following:

  •  Characteristics of the skin: The skin loses its shine and texture and becomes dull and hard to the touch. The skin may erupt.
  • How hair reacts to the disease: Most of these conditions exist in particular areas of the scalp and surrounding skin can be completely normal.
  •  The presence of what may appear to be an infective component to the presentation: It is not unusual for the skin to develop blister type changes with redness that appears infective.
  •  How the disease starts and evolves over time: The various scarring alopecias have distinct evolutionary changes in the skin over time and there may be other elements of the disease impacting other parts of the body. This is where the skill of the dermatologist plays an important role.
  •  Family history of similar diseases: Family history of the dis- ease is common in alopecia areata.
  • The presence of weeping at the skin level may produce wet- ness: Some of these diseases can also be dry and crusty, some have a normal skin, while others have a very fine thin skin over the involved areas.

Scarring alopecia occurs when the hair follicles are destroyed. If the condition attacks the hair follicles directly, it’s called primary cicatricial alopecia; one example is lichen planopilaris (see the fol- lowing bullets). Indirect follicle damage is called secondary scarring alopecia; examples include damage from radiation therapy or a burn injury to the scalp.

Relatively uncommon conditions that can cause permanent, scar- ring hair loss include:

  •  Lichen planopilaris: It often appears in the form of purplish bumps or red-to-purple rims around the hair follicles and can be on the scalp alone or associated with the skin condition lichen planus. Although the cause is unknown, it appears that the body’s white blood cells attack the hair follicles and cause permanent damage to them.
  •  Frontal fibrosing alopecia: More common in postmenopausal women, this condition is characterized by large spaces that appear between hair follicles of normal diameter. A scalp biopsy will reveal many immune cells in the process of destroying the hair follicles they surround.
  •  Pseudopelade: This form of scarring alopecia looks like alopecia areata in its general shape. It’s not a specific disease but rather a pattern of old or burned-out scarring alopecia, result- ing from a variety of causes.
  •  Dissecting cellulitis of the scalp: This condition is characterized by multiple pustules and large cystic nodules in the scalp and can be associated with severe facial acne. It most commonly occurs at the back of the scalp. It’s much more common in people of African descent.

A scalp biopsy can readily determine if hair loss is non-scarring or scarring and therefore permanent. However, determining exactly which scarring condition caused the hair loss can be difficult.

It’s worth repeating that if you’re experiencing hair loss, it’s important to see your doctor to determine the type of loss and whether it’s treatable. And if it is treatable, you should start your treatment as soon as possible in an effort to prevent permanent hair loss.

Lupus: A Scarring and Non-scarring Disease

Lupus is an autoimmune disease that causes inflammation of organ tissue (see the sidebar, “What’s an autoimmune disease?,” earlier in this chapter). Up to half of people with lupus experience hair loss at some point during the course of the disease; hair loss can occur in areas near the temples or be patchy and diffuse. The two main types of lupus are

  •  SLE (systemic lupus erythematosus), which is systemic (meaning it impacts many parts of the body) and may cause non-scarring hair loss. Although it’s an autoimmune disease, SLE spares the hair follicles, so hair grows back after the dis- ease is successfully treated.
  •  DLE (discoid lupus erythematosus), which is localized and may cause scarring hair loss. DLE causes irregular patches of hyperpigmented (skin that is dark) and hypopigmented (skin that appears almost white) skin, along with redness, scales, scarring, and hair follicles devoid of hair. The condition can occur anywhere on the body but is most common on the head and neck, particularly the scalp and ears.

General symptoms of lupus include reddish facial rashes, sensitivity to the sun, mouth ulcers, arthritis, which can be quite disabling, low-grade fevers, and persistent fatigue. Lupus most commonly affects women in the 20–50 age bracket. Blood tests diagnose the condition.

Systemic lupus is a serious disease, and most people who have it are concerned less with hair loss and more with the graver symptoms (such as severe arthritis, diseases of the kidneys and lungs). There’s no specific treatment for hair loss associated with SLE, but medications used to treat the disease may also help with hair loss.

To complicate matters, some medications (such as Plaquenil) used to treat lupus can have the side effect of hair loss. If you recently started on a new medication to treat lupus and have noticed new onset hair loss, be sure to consult your doctor to see if the drug is causing your hair loss.

DLE is a much less serious condition than SLE. Oral medications such as Plaquenil and the local injection of steroids in the plaques of the scalp can control the disease, and if your doctor catches it early, localized hair loss caused by the plaques of DLE may be prevented.

May Cause Side Effects: Medications and Hair Loss

Some medications can do more than cure what ails you: They can cause you to lose hair. The list of drugs that may cause hair loss is huge, but here are a few of the more common ones:

  • Acne medications, such as isotretinoin (Accutane)
  • Antiinflammatory drugs, such as naproxen (Naprox), indomethacine (Indocin), and naproxen (Naprosyn)
  • Antidepressives, such as paroxetine (Paxil), fluoxetine hydrochloride (Prozac), and sertraline hydrochloride (Zoloft)
  • Beta blockers, such as nadolol (Corgard), propanolol (Inderal), metoprolol (Lopressor), and atenolol (Tenormin)
  • Birth control pills
  • Blood thinners, such as warfarin sodium (Coumadin) and heparin
  • Cholesterol-lowering drugs, such as gemfibrozil (Lopid)
  • Gout medications, such as allopurinol (Lopurin or Zyloprim)
  • Seizure medications, such as trimethadione (Tridone)
  • Ulcer medications, such as famotidine (Pepcid), cimetidine (Tagamet), and ranitidine (Zantac)
Other Causes of Hair Loss

Sometimes the disease process that results in hair loss actually has nothing to do with hair. For example, constant or deliberate hair pulling can result in loss of perfectly normal hair, and constant traction on hair from rubber bands or other hair accessories can cause perfectly normal hair to break off. This section looks at a two unique causes of hair loss.

Tearing your hair out: Obsessive compulsive disorders

The expression “I’m pulling my hair out” means the speaker is frustrated or perturbed. Everyone gets the urge to pull out their hair now and then, but for some people, literal hair pulling amounts to an obsessive-compulsive disorder.

An obsessive-compulsive disorder (OCD) is a psychiatric disorder in which a person tries to defuse his or her obsessive thoughts by repeatedly performing compulsive tasks. If you repeatedly tug at your hair, you have a type of OCD called trichotillomania (it’s also known as “trich” or TTM). TTM is non-scarring, so your hair can grow back if you stop pulling and tugging. Usually people with tri- chotillomania pull scalp hair, but they may also yank hair from their eyebrows, eyelashes, and bodies.

The demographics of TTM

Trichotillomania sufferers fall into two groups:

  • Those who intentionally pull out their hair because of an itch or feeling of pain. Sometimes they get a sense of pleasure from hair pulling.
  • Those who pull out their hair by habit and may not realize they’re doing it.

TTM is more common in children than adults, often striking in early adolescence. More women than men suffer from the disorder.

Often the dermatologist is the first to diagnose the problem and then sends the patient to a psychiatrist for treatment. Quite often, patients seek help for their hair loss without realizing that it’s self- induced and that they have trichotillomania.

Treating TTM

Several treatment options are available for trichotillomania. If the sufferer is a child, cutting the hair short so that it can’t be pulled may change the child’s behavior over time.

For older children and adults, self-monitoring can also be a cure. You record the time and situation of hair pulling and the number of hairs pulled in an effort to increase awareness of the behavior. You also may seek behavioral modification or psychotherapy with a mental health professional. Medication is another option; the most common drugs used are antidepressants in the serotonin re-uptake inhibitors class. In addition, Clomipramine, a tricyclic antidepressant, may alleviate symptoms.

Prolonged hair pulling: Traction alopecia

If you have traction alopecia, you lose hair gradually due to pro- longed tension on the follicles. People who wear their hair in tight braids, ponytails, and pigtails are most prone to this problem. It also can result from using tight roller curlers or repeatedly pulling the hair when straightening it. Because of these activities, traction alopecia is more prevalent in women than men and much more commonly seen in people of African descent. If caught early, it’s reversible, but persistent traction alopecia can lead to scarring.

The problem first appears as patchy areas of hair loss on

the periphery of the scalp; eventually these areas can extend further into the scalp and result in large areas of hair loss. The treatment — not putting any more tension on the hair — seems simple, but getting patients to change old habits is never as easy as it seems.

It’s essential to detect the condition early so it can be treated before large amounts of hair are permanently damaged. Late diagnosis often means irreversible loss, and no treatment can make the lost hair grow back again. The only way to restore the hair is through hair transplantation, which is only practical if not too much of the patient’s hair has been lost. (Turn to Chapter 13 for more on hair transplantation.)

Enduring Hair Loss with Chemotherapy

Chemotherapy is the treatment of disease with powerful drugs meant to kill rapidly growing cancerous cells. Because the drugs are so potent, chemotherapy has many side effects, one of which is hair loss. Chemotherapy targets not just cancer cells but all rap- idly growing cells, including hair follicle cells, which is why chemotherapy often causes severe hair loss.

Not all chemotherapy drugs cause hair loss; your doctor will tell you if the drug or drugs you’re taking have this side effect. Some newer chemotherapy drugs are made to specifically target certain cells and spare your hair.

Still, if you’re receiving chemotherapy, it’s likely that all your hair in the actively growing phase will fall out. Because 90 percent of hair is in this phase of the hair growth cycle at any given time, essentially all your hair may fall out during treatment. Different drugs cause different hair loss patterns; with paclitaxel (Taxol), the loss is sudden, while cyclophosphamide (Cytoxin) causes hair to thin but not fall out altogether.

The good news is that your hair usually starts to grow back within six to eight weeks after you stop treatment. You may ask your doctor about topical minoxidil, which has been shown to accelerate the regrowth of hair by almost two months. When your hair does grow back, it may initially be curlier and have a different texture, but it should return to its old self within a year.