Name: 皮膚科医だけど質問ある？【PART2】 | Tech Support | WIRED Japan
Uploaded: 2025-03-10T09:15:19.000Z
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I'm Dr. Maneeb Shah, a board-certified dermatologist, and I'm here today to answer more questions from the internet.

This is Skin Support. ["Skin Support"] At Mia Pinchoff asks, how many layers of skin do we have, ballpark?

It depends on how you look at the layers of the skin.

So there's really three major layers of the skin.

There's the epidermis, which is everything from this purple upwards, the dermis, which is where your collagen is, and then there's the hypodermis, which is your fat and the muscle and everything that's below that.

You'll hear a lot of times five layers of the skin, but they're not talking about the entire skin in general.

They're talking specifically about that epidermis layer, which has four when you're looking at the face and it has five layers when you're looking at the palms and soles.

Stryker asks, is it possible that your lips can become addicted to ChapStick?

So a lot of times people like those fragranced and flavored lip balms, but it turns out that those a lot of times are irritating the skin, which makes you want to actually apply them more often.

Not just that, but if you're somebody who's using flavored lip balms, it's gonna make you lick your lips more often.

And that licking of your lips has enzymes in it that actually breaks down the skin around it, making you want to apply it more.

So my recommendation, avoid fragrances in your lip balms, avoid mint in your lip balms, avoid any flavors in your lip balms and use something that's gentle and fragrance free and you'll probably see a huge benefit and you won't have to apply it as often.

So there's a few things that cause dry skin.

And three, it's things that you potentially are doing wrong.

So from a genetic perspective, a lot of people with eczema or atopic dermatitis, they have dry skin because they have abnormal lipid content in that epidermal layer of the skin.

Low lipids like ceramides or abnormal lipids can cause you to naturally have drier skin.

So if you're in a condition that gets very cold, you have low humidity, we know that when the humidity drops in a room, within one day, your skin actually becomes dehydrated from losing water to the environment.

And then the third thing is things that you potentially are doing wrong.

So using very harsh cleansers, over scrubbing the skin or using hot showers.

Now think about it like this, when you're washing your dishes with cold water, you notice it doesn't remove the oils that well.

But when you wash your dishes with hot water or warm water, it removes oils much more effectively.

When you take a hot shower, it strips away all those natural oils, which can make your skin more dry.

At Cosmo Damage asks, why is vitamin D so important for the skin?

So it's not actually that vitamin D is important for the skin, it's that the skin is important for your vitamin D levels.

About 90% of the vitamin D in your body comes from the skin.

So sunlight actually converts cholesterol into vitamin D, producing most of the vitamin D in your body.

Vitamin D is super important to bone health in general.

When you have low vitamin D levels, your bones actually become very, very soft and they bend and they break very, very easily.

Jay Mick asked, how does one get rid of an ingrown hair?

So what you see here is actually a hair follicle and outside of that hair follicle, you're growing that hair.

But with an ingrown hair, that hair can actually grow out and turn back into the skin or sometimes it gets trapped and it never makes it out of the skin.

While it's embedded in the skin, that can actually cause quite a bit of inflammation and irritation.

And so what you'll actually notice is a red and painful bump.

Now your body can sometimes push out that ingrown hair, but what ends up happening a lot of times is that you actually need to get it physically extracted by a dermatologist or an esthetician that can find the root of that hair and pull it out.

Now you could do this at home if you clean the area and you use tweezers, but definitely be careful because you can develop a worsening infection.

Now, if you want to prevent these ingrown hairs from happening, avoiding much shorter hair, so if you don't shave your hair very short, that can prevent ingrown hairs.

And if you use a glycolic acid exfoliant, that can also prevent ingrown hairs.

And I've noticed in my own personal experience, using an electric trimmer prevents ingrown hairs for me compared to using a traditional razor.

Fun characteristically asks, what is sweat composed of?

How might sweat on one part of the body differ from another?

So when you get sweaty palms and soles, that's majority eccrine sweat.

And that sweat is actually usually pretty odorless.

Now, when we think about body odor, the type of sweat gland that's producing body odor is something called the apocrine gland.

And those apocrine glands are pretty much not active until puberty.

And those are the ones that you find in the armpits, the groin, underneath the breast.

And that's the one that produces that odorous smell.

A lot of people don't realize that when you sweat apocrine sweat, it's actually odorless when you secrete it onto the body.

And then you actually have bacteria on the skin that convert that solution into something that smells bad, ammonia and short chain fatty acids.

And so if you eliminate the bacteria that's converting that sweat, you can actually eliminate body odor.

So things like benzoyl peroxide and chlorhexidine washes are really good at eliminating body odor.

At Roja Aesthetics asks, what is the skin's microbiome?

I don't wanna freak anyone out right now, but if I was to scrape your skin right now and look at it under the microscope, you would have essentially a jungle of organisms living on your skin.

Every single one of you, I don't care how much you wash your face, you would have bacteria, you would have fungus, and you would have little mites crawling around on your skin right now.

And that little jungle is actually called the microbiome.

And they usually live in harmony and cause no problems to the skin.

In fact, when there's a good healthy mix of things growing on your skin, it's actually good for you.

And it's when one type of organism starts to sort of leave the jungle is when you start to develop things like acne.

At FSChick asks, how TF is the skin an organ?

So an organ is supposed to be a collection of tissue that all serve the same purpose.

The skin is considered an organ because its function is to protect you from the environment and also to keep things in the skin.

So if you don't have your skin, which we actually see in people that have severe burns all over the body, you dehydrate very quickly because all the water in your body evaporates and you get infections very quickly because your skin's not protecting you from the environment.

At FameDeLaFleur asks, does retinol cream really work?

I personally use retinol, so I certainly hope that it works.

If you're a skincare enthusiast or even if you're on social media, you probably hear about all kinds of crazy trending ingredients all the time.

And most of them don't stand the test of time.

But retinol on the other hand, which is a vitamin A derivative that we find in skincare has been around now for 50 years and the data is only getting better.

And so tretinoin, which is the active form of retinol, it's found in prescription products, is incredibly effective.

And then retinol is converted to tretinoin in the skin and is a very effective over-the-counter version of this vitamin A derivative.

At Real Nutritious asks, do you know what really causes wrinkles?

With time, there's two things that happen.

So first you wanna look at yourself as a grape when you're a child.

You're filled with juicy fluids and you don't have any wrinkles.

And then you lose that volume with time and you become more like a raisin.

And what is that volume that you're losing?

Collagen, fat, bone, your skin starts to move in the direction of gravity and then you form wrinkles.

One of the most important contributors to aging is sun exposure and also diet.

Diets high in sugar cause glycation, which actually damages your collagen and when you lose that collagen, your wrinkles start to become more prominent.

And so to avoid wrinkles, you wanna protect yourself from the sun, you wanna use healthy diets that are low in inflammation, and you also wanna do things that replenish the collagen, like use things like retinol.

At Trenton Ferg asks, if we shed skin cells every single day, how is it that people have tattoos?

So when we look at our skin shedding every day, we're actually talking about that epidermis layer of the skin that kind of sloughs off every day.

So that's that very top layer of the skin.

But below that, where all your collagen is hanging out, that's your dermis.

And that's actually where they deposit tattoos.

And that's why you don't shed off your tattoos.

And interestingly, the particles of tattoo are too large to actually move and have your body remove them from the dermis.

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皮膚科医だけど質問ある？【PART2】 | Tech Support | WIRED Japan

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