What part of body does not grow hair?

About hair loss and thinning due to cancer treatment

Hair loss or thinning is a common side effect of some cancer treatments.

Do all chemotherapy treatments cause hair loss?

No, some chemotherapy drugs don’t cause any hair loss or only cause slight thinning.

Does radiotherapy cause hair loss?

Yes, radiotherapy can cause hair loss to the part of the body that is being treated.

What helps with hair loss from chemotherapy?

Scalp cooling can reduce the amount of hair loss caused by chemotherapy. Ask your doctor or chemotherapy nurse whether your hospital has scalp cooling and if you can have it.

Hair loss and thinning

Hair loss is one of the most well known side effects of cancer treatment. For many people losing their hair can be distressing and devastating. It can be a constant reminder of your cancer and what you’re going through. But for most people, their hair will grow back once treatment has finished.

Whether you lose your hair depends on:

• the type of drug or combination of drugs you’re having
• the amount (dose)
• your individual sensitivity to the drug
• your drug treatment in the past

Chemotherapy is the type of cancer treatment most likely to cause hair loss.

Hormone therapy, targeted cancer drugs and immunotherapy are more likely to cause hair thinning but can also cause hair loss. Radiotherapy can cause hair to fall out in the area being treated. Hair on other parts of the body is not usually affected.

• mild thinning of your hair
• partial or patchy hair loss
• complete hair loss (alopecia)

Complete hair loss can happen gradually. Or hair may fall out fairly quickly, in clumps.

Hair loss or thinning can also affect your eyelashes, eyebrows and other body hair. For example, pubic hair, underarm hair and chest hair in men.

Chemotherapy

Chemotherapy works by killing dividing cells such as cancer cells. But normal body tissues such as the hair follicles, also have lots of diving cells. This is what makes your hair fall out.

Not all chemotherapy drugs cause hair loss. Some don’t cause any hair loss at all or only cause slight thinning. If your hair is going to fall out, it usually begins within 2 to 3 weeks after treatment starts.

Hair usually grows back once your treatment has finished. However, in some people, it may not grow back or it might grow back patchy. This usually only happens with very high doses of particular drugs.

It might take several months for the hair to grow back. When it does, it might look the same as before, or it may be thicker or thinner. Sometimes it can be a different colour or curlier.

Targeted cancer drugs and immunotherapy

There are different types of targeted cancer drugs and immunotherapy that can cause hair problems. Some of these drugs cause slower hair growth, hair thinning and dry, brittle hair. Some might cause complete hair loss.

A type of targeted cancer drug called epidermal growth factor receptor (EGFR) inhibitors can cause permanent hair loss. But this is usually when you have it long term.

Instead of hair loss, some targeted cancer drugs cause hair growth in unexpected areas of the body. For example, excessive hair on the face or very long, curly eyelashes.

Talk to your doctor or nurse if your treatment is causing excessive hair growth. Ask about the safest way to remove unwanted hair. For example, you (or someone else) might need to carefully trim your eyelashes every few weeks to stop them from irritating your eyes.

Hormone therapy

Hormone therapies are more likely to cause hair thinning than hair loss. An example of this is a drug called tamoxifen for breast cancer.

Ask your doctor or specialist nurse if the drugs you are having are likely to cause hair thinning.

Check if your cancer drug treatment causes hair loss or thinning

Check the name of the cancer drug treatment with your doctor or nurse, then find out about it on our A to Z list of cancer drugs.

• A to Z list of cancer drugs

Radiotherapy

Radiotherapy to the brain always causes some hair loss. If you are having treatment to a particular part of the head, your hair only falls out in that area. You might also have some hair loss on the opposite side of the head, where the radiotherapy beams pass through. This area is called the exit site.

Whether or not your hair grows back depends on the type of radiotherapy you’re having. For example, if you’re having whole brain radiotherapy to treat your symptoms it’s likely that your hair will grow back. Whereas treatment to try to cure cancer uses a high dose of radiation and so permanent hair loss is much more common.

It might take more than 6 months after radiotherapy for your hair to grow back. If your hair does grow back it may not be quite as thick as before and in some people can be patchy.

• Read more about radiotherapy treatment

Reducing hair loss from chemotherapy

Your doctor suggests the best treatment for you. But sometimes there is a choice of drugs you can have.

Speak to your doctor if you find the thought of losing your hair very upsetting. They might be able to suggest a treatment less likely to cause hair loss.

Your doctor might also talk to you about ways of reducing hair loss from chemotherapy treatment. They may suggest you try scalp cooling.

Unfortunately, there is no known way to prevent hair loss from:

• radiotherapy
• hormone therapy
• targeted cancer drugs
• immunotherapy

Scalp cooling

Scalp cooling can sometimes reduce the amount of hair loss.

Scalp cooling lowers the temperature of your scalp and reduces the blood flow in the scalp. This reduces the amount of chemotherapy that reaches the hair follicles on your head. With less of the chemotherapy drugs getting to the hair follicles, the hair is less likely to die off and fall out.

There are different types of scalp cooling. These include:

• cold cap. This is a hat filled with a gel that is chilled before you put it on
• refrigerated cooling system. You wear a cap that is attached to a machine that pumps liquid coolant into the cap

You can ask your doctor or nurse if your hospital has scalp cooling and which type they use. They can explain exactly what happens.

When not to have scalp cooling

Scalp cooling is not suitable for everyone. You won’t normally have scalp cooling if there is a high risk that there might be cancer cells in your scalp. Scalp cooling is also not recommended for people:

• with blood cancers such as leukaemia and lymphoma
• who are going to have scalp radiotherapy

You would not have scalp cooling with continuous chemotherapy through a pump or with chemotherapy tablets. This is because you would have to wear the cold cap for 24 hours a day.

Possible risk of scalp cooling

Scalp cooling only blocks certain chemotherapy drugs and doesn’t work for everyone. So you might still have hair thinning, or lose your hair completely. We can only tell whether it will work for you once you try it.

Your doctor might not suggest scalp cooling if they are worried about the risk of cancer cells being left on the scalp. This can lead to cancer spread in the scalp (scalp metastases).

Researchers did a systematic review of studies in 2018. The review showed that the risk of cancer spreading to the scalp after using a cold cap was very small.

Things to think about

You stay at the hospital for longer if you have scalp cooling. You need to wear the cap before, during and after you have the chemotherapy drugs into your bloodstream.

The time varies depending on the drug and type of cold cap system your hospital has. For the Paxman scalp cooling system, you might wear the cap:

• for about 30 to 45 minutes before treatment depending on your hair type
• during treatment for as long as it takes to receive the drugs
• after treatment for a minimum of 20 to 90 minutes depending on the drugs you have had

Your nurse might ask you to dampen or wet your hair before you put on the cap or cooling system. This is to improve contact between the scalp and cap and lower the temperature of the skin on your scalp. You also have a small amount of conditioner added to help in removing the cap after you have finished treatment.

Research suggests that scalp cooling with Afro Caribbean hair is not as successful. So your nurse might recommend you have longer periods of scalp cooling if this applies to you.

Side effects of scalp cooling

Scalp cooling can make you feel cold all over and uncomfortable. At the start, you might feel very uncomfortable for around the first 15 minutes. This should then ease. Let your nurse know if you can’t cope and want to stop the treatment. Scalp cooling can also:

• give headaches or pain in your forehead
• make you feel sick
• make you feel dizzy and light headed

Tips for helping you cope with scalp cooling:

• take extra layers to put on
• take or ask for a blanket
• drink hot drinks to help you feel warmer
• ask for some painkillers before the scalp cooling starts

Talk to your specialist nurse if you want to try scalp cooling. You can discuss the possible risks with your specialist if you are worried.

• Read about coping with hair loss

References

• Scalp Cooling Policy for Adult Cancer Patients receiving Alopecia Inducing Chemotherapy/SACT
  NHS Northern Cancer Alliance, 2018
• Prevention and management of dermatological toxicities related to anticancer agents: ESMO Clinical Practice Guidelines
  ME Lacouture and others
  Annals of Oncology, 2021. Vol 32, Issue 2. Pages 157-170
• Scalp Cooling Guidelines for Adult Oncology Patients
  West Midlands Expert Advisory Group for Systemic Anti-Cancer Therapy (SACT), 2017
• Scalp Cooling Guidelines for Adult Oncology Patients. West Midlands Expert Advisory Group for Systemic Anti-Cancer Therapy (SACT)
  S Neal and S Toland
  NHS England, 2017.
• Factors Influencing the Effectiveness of Scalp Cooling in the Prevention of Chemotherapy-Induced Alopecia
  M C Manon and others
  Oncologist. 2013. Volume 18, Issue 7. Pages 885–891
• The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in if you need additional references for this information.

We Might Finally Know Why Humans Don’t Have Hair on Some Body Parts

(Remains/iStock)

There’s no other way to say it: human hair is strange. Compared to most other mammals, human beings are decidedly naked, and the little fuzz that we do have is oddly patchy and quite diverse.

The most obvious of our bizarre bald regions are perhaps the soles of our feet and the palms of our hands. Here, our sleek and hairless skin sets us apart from other mammals, such as rabbits and polar bears, who both sport fur along their paws.

It’s an enigma that continues to puzzle, but researchers may now have an explanation for why some parts of the human body have hair and others don’t.

A new study on mice has revealed an important molecular pathway that keeps the undersides of our feet and hands as smooth as a baby’s bottom.

The explanation is centred on a small molecular messenger, called a Wnt protein, which carries information between cells about the initiation, spacing, and growth of body hair.

«We know that Wnt signalling is critical for the development of hair follicles; blocking it causes hairless skin, and switching it on causes formation of more hair,» senior author Sarah Millar, a dermatologist at the University of Pennsylvania, told Cosmos.

«In this study, we’ve shown the skin in hairless regions naturally produces an inhibitor that stops Wnt from doing its job.»

The inhibitor is a protein called Dickkopf 2 (DKK2), and when it is removed from mice completely, the researchers noticed something curious. While the mutant mice continued to be hairy in all the right spots, the normally bare regions of their paws were now also sprouting little hairs.

In normal mice, the plantar region of the foot is free of fur, but in all 40 mutant mice, the researchers found fully-formed, mature hair follicles embedded in that very spot. And even when these hairs were plucked, these unusually hirsute bits grew back, just like normal fur.

When the researchers turned their attention to rabbits, they noticed something similar. Like polar bears, rabbits also grow hair on the bottoms of their feet, probably to keep their toes warm while they hope across snow and ice.

In this case, DKK2 also appears to play a role – or, rather, its absence does. In rabbit plantar skin, the study found that DKK2 is not expressed at high levels, and this is probably why fur is able to develop there.

The results were unexpected. When the study was first started, the researchers thought that DKK2 might be responsible for the pattern of hair follicles that develops on the body. But the new findings suggest that its role is kind of the opposite.

The researchers now think that the presence of DKK2 is responsible for keeping certain parts of the body free from hair. So, in certain cases where this inhibitor is not present, the Wnt signalling pathway is left to its own devices, activating the appropriate stem cells, called β-catenin, and causing hair follicles to develop in places where they shouldn’t.

As for why this happens, Millar and her team think the presence or absence of DKK2 is probably based on evolutionary benefits.

For instance, while rabbits and polar bears might need hairy paws to survive, if human hair extended all the way to our hands and feet, it would probably make our lives a hell of a lot more difficult, not to mention messy.

At this point, it’s still not clear exactly why humans would have developed bare hands and feet, but there are a few hypotheses.

Some suggest that it could be about sexual selection; others say it has more to do with thermoregulation, as we moved from the forests to the Sun-beaten savannah; while still others think our nakedness protects us from external parasites, like lice and other pesky bugs.

There are even those who think there is no evolutionary benefit whatsoever, and this was just a sneaky little trait that hitched a ride into the future.

Regardless of which explanation is correct, if the new findings extend to humans, it means that with just one slight genetic change, we could get hair to grow on the otherwise bare surface of our hands and feet.

As such, the authors of the study hope that one day, their research might help us figure out a way to block or promote the growth of body hair.

This sort of treatment could be extremely useful for a whole variety of health issues, including male pattern baldness, and helping to treat burns patients and people with skin issues, such as psoriasis.

«While more research is needed to improve our understanding of this pathway, our results suggest that therapeutics capable of decreasing levels of Wnt/β-catenin signaling in the skin could potentially be used to block growth of unwanted hair, and/or to treat certain skin tumours,» says Millar.

«Conversely, if delivered in a limited, safe, and controlled way, agents that activate Wnt signaling might be used to promote hair growth in dormant hair follicles in conditions such as male pattern baldness.»

This study has been published in Cell Reports.

Hair Loss (Alopecia) and Cancer Treatment

Some types of chemotherapy cause the hair on your head and other parts of your body to fall out. Radiation therapy can also cause hair loss on the part of the body that is being treated. Hair loss is called alopecia. Talk with your health care team to learn if the cancer treatment you will be receiving causes hair loss. Your doctor or nurse will share strategies that have help others, including those listed below.

Ways to manage hair loss

Talk with your health care team about ways to manage before and after hair loss:

• Treat your hair gently. You may want to use a hairbrush with soft bristles or a wide-tooth comb. Do not use hair dryers, irons, or products such as gels or clips that may hurt your scalp. Wash your hair with a mild shampoo. Wash it less often and be very gentle. Pat it dry with a soft towel.
• You have choices. Some people choose to cut their hair short to make it easier to deal with when it starts to fall out. Others choose to shave their head. If you choose to shave your head, use an electric shaver so you won’t cut yourself. If you plan to buy a wig, get one while you still have hair so you can match it to the color of your hair. If you find wigs to be itchy and hot, try wearing a comfortable scarf or turban.
• Protect and care for your scalp. Use sunscreen or wear a hat when you are outside. Choose a comfortable scarf or hat that you enjoy and that keeps your head warm. If your scalp itches or feels tender, using lotions and conditioners can help it feel better.
• Talk about your feelings. Many people feel angry, depressed, or embarrassed about hair loss. It can help to share these feelings with someone who understands. Some people find it helpful to talk with other people who have lost their hair during cancer treatment. Talking openly and honestly with your children and close family members can also help you all. Tell them that you expect to lose your hair during treatment.

Ways to care for your hair when it grows back

• Be gentle. When your hair starts to grow back, you will want to be gentle with it. Avoid too much brushing, curling, and blow-drying. You may not want to wash your hair as frequently.
• After chemotherapy. Hair often grows back in 2 to 3 months after treatment has ended. Your hair will be very fine when it starts to grow back. Sometimes your new hair can be curlier or straighter—or even a different color. In time, it may go back to how it was before treatment.
• After radiation therapy. Hair often grows back in 3 to 6 months after treatment has ended. If you received a very high dose of radiation your hair may grow back thinner or not at all on the part of your body that received radiation.

Talking with your health care team about hair loss

Prepare for your visit by making a list of questions to ask. Consider adding these questions to your list:

• Is treatment likely to cause my hair to fall out?
• How should I protect and care for my head? Are there products that you recommend? Ones I should avoid?
• Where can I get a wig or hairpiece?
• What support groups could I meet with that might help?
• When will my hair grow back?

Radiation Therapy Audio Transcript

What To Do About Hair Loss (Alopecia)

Narrator:
What to do about hair loss during radiation therapy.

Let’s listen in on a support group as the group’s leader, Janet, opens the discussion by talking with members about coping with hair loss, also called alopecia.

Janet:
Okay—let’s get started.

First, I want to make sure you all know that people tend to lose hair only in the area where they get radiation therapy. Tonight, we’re going to talk about different ways to prepare for hair loss and what can make this a little easier. Who would like to start?

Kim:
I will. [sigh] I hate that my hair is already thinning. I’m getting radiation therapy to my head, and I wake up to a new handful of hair on my pillow each morning. I’m not a vain person, but I love my hair.

Janet:
Kim, hair loss can be very hard. I’m so sorry. Most people find that their hair starts to fall out in the area where they are getting radiation therapy, about 2 to 3 weeks after their first radiation therapy session.

Kim:
That makes sense—I started my first treatment 3 weeks ago.

Rodney:
It helped me that I started out half bald to begin with. But I know what you are saying, Kim. I would wake up to hair on my pillow each morning. I decided to shave my hair off before it fell out on its own from treatment. I used a good electric razor—learned the hard way when the plastic one cut my scalp.

Kim:
Rodney—the bald look is great for you. I’m just not ready to shave it all off right now.

Janet:
Rodney, thanks for letting us know what worked well for you. Who else would like to share?

Cara:
Well—first I cut my hair short so the shock factor was less. And I got a wig before all my hair fell out. The first one I got matched my natural hair color. That one was free. Then I thought, hey, I’ve always wanted to be a redhead—so I bought a red wig.

Kim:
The first one was free?

Cara:
Yes. The nurse gave me the number of a place that supplies wigs at no charge. But wigs can be hot, especially in the summer. That’s why you see me in this colorful scarf wrapped around my head like a turban. Personally, I think a turban is the way to go!

Miguel:
I see a lot of women at the hospital wearing bandannas. Some men too.

Cara:
I’ve seen lots of people at the clinic in baseball caps!

Kim:
These are great suggestions. Thanks, guys. But I still need to know one thing—Janet, will my hair grow back?

Janet:
Your hair may grow back in 3 to 6 months after your treatment is over. It really depends on the amount of radiation you get. People who get very high doses may not see their hair return. In the meantime, wash your hair gently with a mild shampoo and pat it dry. I’d also avoid using a hair dryer.

Kim:
Okay, Janet, thanks. And thanks, everyone, for sharing your ideas. Looks like I’m going scarf shopping!

Cara:
Want some company?

Kim:
Sure, that would be great. Do you think we could go tomorrow afternoon?

Narrator Summary:
Hair loss can be difficult for both men and women. It’s important to remember that people tend to lose their hair only in the area where they get radiation. Most often, hair grows back 3 to 6 months after you complete treatment.

If you’d like to wear a wig, talk with a nurse or a social worker where you receive treatment. In some cases, your wig may be free or covered by your health insurance.

And as some group members shared, you can always wear a scarf, bandanna, cap, or nothing at all on your head. Choose whatever works and feels best for you.