Skin Case Study and Articles

Click on this link to watch a video and answer the questions

Multiple Choice

What are the three layers of the skin?

• Epidermis, Dermis, Hypodermis
• Epidermis, Subcutaneous, Dermis
• Epidermis, Dermis, Epidermis
• Epidermis, Dermis, Muscle

Multiple Choice

What substance in the epidermis makes hair and nails strong?

• Keratin
• Melanin
• Collagen
• Elastin

Multiple Choice

How often are the cells in the epidermis completely replaced?

• Every 4-6 weeks

• Every year
• Every 3 weeks

• Every 14 days

Multiple Choice

What causes the skin to tan?

• melanin production in the skin.

• Drinking water regularly
• Eating certain foods
• Exposure to cold weather

Multiple Choice

Which layer of the skin is the thickest?

• Epidermis
• Dermis
• Stratum corneum
• Hypodermis

Multiple Choice

What makes the skin elastic and stretchable?

• Collagen and elastin fibers in the skin.
• Keratin and melanin in the skin.
• Fat cells beneath the skin surface.
• Blood vessels and nerves in the skin.

Multiple Choice

Why can't you tickle yourself?

• You can only tickle yourself if you are very flexible.
• Tickling requires another person's touch to be effective.
• Your nerves are too desensitized to feel your own touch.
• You can't tickle yourself because your brain predicts the sensation and reduces the response.

Multiple Choice

What role does fat play in the hypodermis?

• Fat serves as a primary source of hydration in the hypodermis.
• Fat is primarily responsible for skin pigmentation.
• Fat provides insulation, energy storage, and cushioning in the hypodermis.
• Fat aids in digestion and nutrient absorption.

Multiple Choice

What happens when a bacterium penetrates all skin layers?

• It becomes part of the skin flora

• Macrophages destroy it

• It strengthens the skin's immunity

• The bacterium becomes harmless and dies.

Multiple Choice

How does scar tissue differ from ordinary skin tissue?

• It has parallel fibers for faster repair

• Scar tissue is identical to ordinary skin tissue in structure and function.
• Scar tissue is less elastic

• Scar tissue contains more fat

Lost in the Desert

​Part 1

Mark, a Caucasian, 35 year old mal weighing approximately 70 kg started a three-hour drive across the desert on US 95 from Yuma, AZ, to Blythe, CA.  He set out at 7am on what was expected to be a very hot July day.  He anticipated that it would take him 3 hours to reach Blythe- plenty of time to make his 11am appointment with Sarah, his fiancée.  When he failed to appear my noon, Sarah become concerned and called the highway patrol.

By 12:30pm, Search and Rescue Officer Maria Arroyo, who was patrolling nearby, reported finding an abandoned car on the side of the road with a damaged radiator that matched Sarah’s description of Mark’s vehicle. Maria noticed shoe prints leading into the desert toward some low mountains in the distance.  At that Point Maria celled for helicopter, consulted her GPS and relayed the exact coordinates to base.

By 1pm Henry Morning start, paramedic and a member of the helicopter crew, reported a shirtless, hatless man wandering down a desert wash.  The local radio station reported at about the same time that the temperature was about 105F in the shade (and there was not much of that). The relative humidity was less than 5%.  The helicopter had found Mark, as identified by his driver’s license. Mark was still conscious but clearly delirious.  Henry also noted that mark was weak, nauseous, disoriented, and complaining of a headache.  He is blood pressure was low, 70/50 (normal is 120/80) and he was not sweating despite the oppressive heat.  His body temperature was 105 (normal is 98.7).  The patient was diagnosed as having a heat stroke. The paramedic also noted first degree burns on his face and back

Multiple Choice

What caused Marc’s weakness, nausea, disorientation, headache and low blood pressure?

 

• Mental Illness

• Allergic reaction
• Heart Attack

• heat exhaustion/str

Multiple Choice

Why isn’t Marc sweating?

• Marc is dehydrated from sweating in 5% humidity

• Marc is not sweating because he was not hot

• Marc was not sweating due to not exercising

• Marc is not sweating because the humidity is high

Multiple Choice

Would you expect Marc’s heart rate to be increasing or decreasing?

• Fluctuating wildly
• Increasing
• Decreasing rapidly
• Stable

Multiple Choice

If Marc had unopened Coke in his car would it have benefitted him at all to drink it?

• No, because sugar dehydrates you.

• No, it would have made him feel worse. by increases his sugar

• Yes, it would have benefitted him by increasing sugar

• Yes, becauise Coke contains water.

Multiple Choice

Given the conditions what should Henry do to save Mark?

• Oral rehydration

• Give him a blanket and warm him up

• Try to move Mark without assessing the injury.
• Give him a Coke

Part 2

July 13^th, PM

Henry started oral rehydration with an isotonic solution containing electrolytes, glucose and water?

 

As Mark recovered in the hospital he related what happened to him earlier in the day.  Since he was a newcomer to the desert areas, he saw no need for sunblock or extra water on his trip.  He recalled seeing a coyote dart out from behind two bushes and hitting the animal.  The area was so isolated that his cell phone was useless.  He waited for a while but at about 10am as the sun climbed he saw some water in the distance and thought it might be the Colorado River.  The “river” was actually a mirage, as he realized after walking a considerable distance. He then started to become confused and couldn’t find his way to the highway.  Eventually he became very hot and threw away his shirt and hat.

Multiple Select

Why did Henry give Mark an isotonic solution rather than just distilled water?

• Distilled water would have caused his cells to burst by increasing the water too fast

• Isotonic solutions are too expensive to use.
• Isotonic Solutions do not contain water and are therefore better at helping the body during a heat stroke

• Isotonic solutions contain electrolytes as well as water.

Multiple Choice

Assuming Mark lost 4L of water what percentage of his body weight did he lose?

• 3.33%
• 5.71%
• 10%
• 2.5%

Multiple Select

What did Marc do that increased his chance of sunburns?

• Didn't wear sunscreen

• Stayed in the shade for most of the day.
• Took his hat and shirt off

• Applied sunscreen but it was expired.

Part 3

After he left the hospital, Mark saw extensive new melanin formation in his skin.  Much later Mark noticed some new moles on his shoulders. The moles grew, changed color and bled.

Multiple Choice

Should Mark be concerned about the moles? Why?

• Yes, they could be cancer

• Moles are only a concern if they are large.
• Mark should ignore the moles completely.
• No, the moles are harmless.

Multiple Choice

What vitamin might Marc have an increase of following this incident? Why?

• Vitamin B12
• Vitamin C
• Vitamin A
• Vitamin D

Tattoo You

Last Saturday, while I was visiting Fatty's Tattoos and Piercings, a college-aged woman in a hoodie walked in and asked for a tattoo, her first, right on the spot. "I want a red-tailed hawk feather," she told the artist on duty at the Washington, D.C., tattoo parlor. He peppered her with questions: How big? What style? She alternated between a blank stare and a furrowed brow: "I have a photo on my phone of the feather that I like, I could show you that?"

The artist rubbed his beard and told her he didn't do realistic tattoos. Maybe they should set up an appointment for her sometime next week, with another artist, he offered. Between the lines, he seemed to say, "This will be permanent, so I don't want to give you the wrong tattoo."

But considering how many changes skin weathers – burns heal, scars fade and wrinkles set in – it's sort of unbelievable that tattoos do stick around. Recently, a group of French scientists looked into how that works, hoping to use the knowledge to improve tattoo removal.

So, first, of course, they gave some mice tattoos. The mice didn't get Mom tattoos on their tiny biceps. Instead, they got tail tats – three stripes of green ink – for researchers to study. "The thing is, the mouse skin can be super fragile, much more fragile than human skin," says Sandrine Henri, an immunologist at the Centre d'Immunologie Marseille-Luminy.

 

If you zoom way in on any tattoo, it's really just a bunch of cells holding tight to ink particles. From the mice's tail tattoos, Henri and her colleagues identified one type of cell that captured ink particles and stayed in place, the dermal macrophage.

The researchers thought they might be able to disrupt the tattoos by destroying the macrophages that had locked up the ink. So they engineered mice whose macrophages — and only those cells — would shrivel in the face of a specific toxin, and then injected that compound into these special, tattooed mice.

But it didn't work. The messed-up macrophages released their ink particles, but the color persisted. It turns out that new macrophages quickly took over the job of holding the tiny flecks of ink in place, and the mice kept their sporty green-striped tails.

Open Ended

What does the work of the group of French scientists on mice tell us about the permeance of tattoos?

Tattoo You

But if it were possible, Henri says, to use an ointment, or a drug, to delay those replacement macrophages, it might improve tattoo removal for mice and humans. The researchers' findings appeared Tuesday in the Journal of Experimental Medicine.

 

To think about removing ink from human shoulders, rather than mouse tails, it helps to know how tattoos appear. In broad strokes, we understand this process, says Bruce Klitzman, a biomedical engineer at Duke who once worked on creating an erasable tattoo.

 

As a tattoo artist outlines a yin-yang symbol on someone's shoulder, a solid needle loaded with ink pierces the tattoo-ee's skin, or epidermis, and the needle's exit lets pigment flow into a second layer of skin, the dermis, Klitzman says. But any self-respecting immune system treats all visitors – including the ink particles meant to create a wolf's face on your forearm – as unwelcome. So skin cells mount a multilevel attack on the ink particles.

First, the cells that weren't hit by the tattoo needle block out guests, Klitzman says. Only a fraction of the ink an artist lays down actually makes it into the dermis, and this is also why new tattoos tend to leak ink as they heal. Newly tattooed skin swells, the same way it would respond to any other wound, and blood and lymph ferry away the smallest bits of ink. For the remaining pigment particles, the next order of the immune system's business is consuming the foreign invaders, to try to destroy them.

That's where the macrophages, the cells Henri studied, come in. They're specialized immune cells – their name means big eater in Greek – and their job is to slurp up interlopers, says Klitzman. "Macrophages can basically swallow many, many tattoo pigment particles, almost like a vacuum cleaner, just go along and suck up all those particles," he says. Usually, a macrophage digests the invaders it devours, using acid to rip its enemy apart. It's a good strategy for killing bacteria and viruses, but not for tattoo pigments. Acid has little effect on the ink ingredients.

That means a macrophage that has gorged on ink has no way to finish its job. Eventually, the pigment-filled macrophages dial back their attack, content to contain the threat, even if they can't completely neutralize it. "They just sit there like a full vacuum cleaner bag," says Klitzman.

Open Ended

How does the interaction of the integumentary system (skin) and lymphatic system (immunity) make tattoos permeant

Another type of cell, called a fibroblast, is also known to take in some ink particles in human skin. Together, the macrophages and fibroblasts bind enough ink for the image of, say, a carrot or feather to appear on your calf. Those cells and the pigment inside them can hang around for years. But all cells die eventually, which brought Henri and her team to their question: How do tattoos stay put as individual cells die?

Their work confirms that even when macrophages die and release their pigment particles, other macrophages quickly gobble up the ink, keeping it in place. Even when the researchers grafted one mouse's tail tattoo onto another mouse's back, the second mouse's own macrophages carried the skin graft's tattoo. "The cells from the graft died and released the ink, and the host mouse's cells captured it," Henri says.

All of that, basically, underscores why tattoo removal is really, really difficult. Laser removal is an option, says Jared Jagdeo, a dermatologist at University of California, Davis. Tuned to a wavelength specific to a tattoo's colors, "lasers are able to break apart tattoo particles," he says. The bursts of energy bust ink "from larger boulders into smaller rocks, and then into fine pebbles which then can be swept away by the lymphatic system."

But laser removal is far from perfect. The process of blurring ink beyond recognition can take many sessions, spaced weeks apart, at a couple hundred dollars a visit. Laser pulses irritate skin, and people show re-uptake of ink similar to Henri's mice, Jagdeo says. He uses anti-inflammatory drugs to help tame that response, but it's really difficult to remove all evidence of a tattoo. "Tattoos are at their baseline permanent, so if [someone gets] a tattoo they should plan on having it for a while," he says.

Back at the tattoo shop, I don't know if the woman with the red-tailed hawk feather ever managed to get her tattoo. Either way, I hope she's happy with her decision. For now, tattoo removal is still a challenge.

Open Ended

Why does dermatologist Jared Jagdeo recommend that individuals carefully consider their tattoo choice?

​Gene Therapy for “Butterfly Children” 🦋

Videos of the “butterfly children” are difficult to watch. The name comes from the delicate skin of people who have epidermolysis bullosa, which is reminiscent of the fragility of a butterfly’s wings. The slightest touch causes painful blisters and peeling skin.  Parents can be carriers of Recessive dystrophic epidermolysis bullosa (RDEB)  without having any of the effects. RDEB affects about 1 in every 20,000 births in the United States. 

Parents of RDEB children provide intensive care for their children, which includes daily full body bandage changes and use of antibiotics and antiseptics.  These bandages are made of special polymers that have low adhesion so they don’t tear the skin if a parent pulls a bandage off. 

The daily bandage changes, pricking of blisters, and removing flaky skin aren’t all the requirements. Bathing can take hours. Complications include anemia, malnutrition from mouth and esophagus sores that make eating nearly impossible, and skin cancer.  Scarring of skin can cause the  fingers and toes  to fuse together creating “mitten” deformities.   Patients may need  surgical procedures to cut fingers free.  Over time rigid joints and deformities emerge as the damaged skin shrinks and tightens muscles and tendons, causing contractures, which further reduces mobility.

Multiple Choice

What part of the body is affected by epidermolysis bullosa?

• Skin

• mucles

• Bones

• Digestive System

Multiple Choice

How is the disease currently treated?

• It is not treated

• daily bandaging and use of antibiotics and antiseptic

• collagen transfusions

• skin grafts

In healthy skin, anchoring fibrils made mostly of Type VII collagen protein knit the thin epidermis to the dermis below. In RDEB, any of 200 mutations prevent the formation of the fibrils.  Gene therapy may offer hope for repairing these mutations.

Gene therapy uses viruses to deliver functional COL7A1 genes, which encode the collagen, into cells taken from patients and growing outside the body (“ex vivo”), and 

then injects the doctored self-cells into selected areas of skin. 

Multiple Choice

What is the role of Type VII collagen in skin?

• Type VII collagen is primarily responsible for skin pigmentation.
• Type VII collagen helps in the production of sweat glands.
• Type VII collagen acts as a barrier against UV radiation.
• Type VII collagen anchors the epidermis to the dermis.

Multiple Choice

What is the sources of the modified fibroblast?

• Patients own cells that have been modified

• Donor healthy cells

• Lab created cells

RDEB gene therapy is localized, and would coincide with patients’ routine hospitalizations, treating one skin area at a time. In younger children with RDEB, wounds start emerging on the body before they become immobile with contractures by their early teens.  One of the clinical strategies is to treat earlier and prevent these  small areas from becoming larger areas. Focusing on certain areas, like the fingers,may better improve quality of life. 

Fibrocell, a cell and gene therapy company, is targeting fibroblasts, and described  the effect of their product on five wounds treated in three adults. At the 12-week mark four of the wounds were greater than or equal to 70% healed and type VII collagen produced, although anchoring fibrils were not yet observed. 

Multiple Choice

How is the correct gene added to the cells?

• Bacteriophage

• Virus containg the gene

• It is not injected into cells but into the patient's body

• Directly into the patient

Multiple Choice

This type of gene therapy has only been effective

• On the patients entire body

• In small wounded areas

• It has not been effective

Open Ended

At the 12-week mark four of the wounds were greater than or equal to 70% healed and type VII collagen produced, although anchoring fibrils were not yet observed. 

What is the importance of the underlined part of the sentence?

Melanin- Umbrellas of our Skin

Umbrellas are not just for rain; they can also shade us from the sun.

Dangerous Ultraviolet Rays

In addition to visible light, the sun produces invisible light called ultraviolet (UV), which has a greater effect on our skin. Depending on the amount of exposure, UV light can be either beneficial or damaging. With moderate exposure, UV promotes the production of vitamin D in our skin, an essential for building strong bones and teeth. In larger doses, however (and especially at a certain wavelength), UV light can damage our skin, producing burns, premature skin aging, wrinkling, mutations, and skin cancer.

Melanin to the Rescue

Like all good sunshades, the umbrellas in our skin are darkly colored. The dark pigment in our skin, called melanin, is typically black or brown. This protein is produced by special cells, called melanocytes, which are located in the lowest level of our epidermis (the surface layer of our skin,

Multiple Choice

Moderate UV light exposure is good because

• It helps in reducing skin elasticity.
• It causes premature aging of the skin.
• it aids in vitamin D production.

• It increases the risk of skin cancer.

Multiple Choice

Too much UV light is bad because

• It helps in the production of vitamin D.
• It can improve skin health and appearance.
• It can cause skin damage and increase the risk of skin cancer.

• It has no effect on the skin at all.

Melanocytes themselves are not the umbrellas of our skin. They merely produce the melanin for our skin, in the form of tiny granules called melanosomes.

Then they transfer the granules to certain epidermal cells in the lowest layer of our epidermis, where they block the damaging UV that penetrates our skin. In other words, melanocytes are like pigment factories that ship pigments (melanosomes) to other cells where the pigment is needed.

The mechanism to transfer the granules is itself amazing. The melanocyte is a highly branched cell with long, slender projections, or processes (Figure 2). The melanocyte makes the melanosomes which then move out to the tips of the cell processes. The epidermal cells then “bite off” the tips of these processes, bringing the granules inside their cell.

Once inside, the melanosomes are moved and arranged to form a dark “cap” over the epidermal cell’s nucleus. This pigmented cap serves as a tiny umbrella for the nucleus, specifically blocking the most damaging wavelength of the UV light (Figure 2)
UV radiation is most damaging when the epidermal cells are dividing to produce new cells. At this critical time, UV can damage the DNA (genetic information) in the nucleus, resulting in mutations and skin cancer.

The only cells that face this danger are the stem cells, the only cells in the epidermis capable of dividing. These cells reside in the deepest layer of the epidermis. And amazingly, only these vulnerable stem cells get the precious melanosomes.

Multiple Choice

What are melanocytes?

• Melanocytes are cells that produce melanin

• Melanocytes are responsible for producing insulin in the pancreas.
• Melanocytes are a type of white blood cell that fights infections.
• Melanocytes are cells that store fat in the body.

Multiple Choice

What are melanosomes?

• Melanosomes are organelles that store carbohydrates.
• Melanosomes are organelles that produce and store melanin.
• Melanosomes are responsible for producing insulin.
• Melanosomes are a type of skin cell that absorbs UV light.

Multiple Choice

Why are melanosomes considered the umbrella of your skin?

• Melanosomes are responsible for skin elasticity.
• Melanosomes help in the healing of skin wounds.
• Melanosomes protect skin cells from UV radiation by absorbing harmful rays.
• Melanosomes produce vitamin D for skin health.

There Are No “White” People

Human skin is normally never truly white, though some people have less melanin in their skin than others. Surprisingly, all humans, regardless of the shade (“color”) of their skin, have approximately the same number of melanocytes per square inch of skin.

Even albinos have melanocytes, but they produce colorless, rather than pigmented, melanosomes. The granules are colorless because the enzyme necessary for producing melanin is either missing or defective.

Interestingly, these colorless melanosomes are still taken into the epidermal stem cells, where they form an umbrella just as in normal skin. The result, however, is something like a clear plastic umbrella—not very good for warding off the sun.

Some people have darker skin than others, not because they have more melanocytes but because they retain a greater amount of melanin after the cells are no longer able to divide. People with lighter shades of skin break down most of their melanosomes.

While DNA is less vulnerable to UV when the cells no longer divide, retaining more pigment is still advantageous. People with darker skin are more resistant to sunburns and skin cancer. Yet people with very dark skin face another problem—they may not be able to produce enough vitamin D.

Multiple Choice

Albinos have no melanocytes

• True

• False

Multiple Choice

What color are the melanosomes of albinos?

• Colorless or transparent
• White
• Black
• Brown

Multiple Choice

Why are some people's skin darker than others?

• Some people's skin is darker due to higher levels of melanin

• Skin color has no relation to genetics.
• Darker skin is a result of living in colder climates.
• Skin color is determined solely by diet.

Multiple Choice

Are there any advantages to having darker skin?

• Yes, darker skin has advantages such as better UV protection and reduced risk of skin cancer.
• Darker skin leads to higher rates of skin cancer.
• Darker skin is less attractive in all cultures.
• Darker skin has no impact on UV protection.

​Impact of melanin on vitamin D production and synthesis

A person’s vitamin D level is also determined by the amount of melanin in their skin, the pigment that influences skin tone. The more melanin, the darker the skin tone. The less melanin, the lighter the skin.

The amount of melanin in the skin affects vitamin D status because the skin depends on UV rays to synthesize vitamin D, and darker skin inhibits its production. It takes about 15 minutes in the sun for a person with lighter skin to generate enough vitamin D for the day, whereas a person with darker skin needs anywhere from 30 minutes to three hours.

Melanin absorbs harmful UV radiation and therefore protects cells against DNA damage from sun exposure.

Populations with higher levels of melanin who live at high latitude are most likely to have vitamin D deficiency. But that may be only because sun exposure for most people living at higher latitude – in cold weather that requires protective clothing year-round – is very limited.

Multiple Choice

Are there any disadvantages to having darker skin?

• Darker skin is always considered more attractive.
• Darker skin has no impact on health.
• Darker skin provides better protection against UV rays and wrinkles

• Darker skin can prevent UV light from making Vit D

​Do people of color need sunscreen?

There’s a common misconception that darker skin tones provide full protection from sun exposure — but that’s just as false as the idea that getting a base tan will protect you from a sunburn.

People of color should wear sunscreen every day to protect their skin from sunburn and more prevalent skin cancers that are on the rise, like basal cell carcinoma and squamous cell carcinoma.

But more than that, sunscreen has numerous other benefits that can help with conditions like hyperpigmentation, melasma and melasma mustaches — all conditions characterized by dark spots or patches on your skin that are worsened by sun exposure.

“If you have dark spots or even melasma, you can spend all your money on all of the various treatments, but if you’re not wearing sunscreen, those products won’t help. Every time the sun hits your skin, it makes those spots darker and stimulates more melanin production,” Dr. Williams explains.

“This includes when you’re directly in the sun and when you’re inside. Sunlight that comes through windows, light from your phone, light from your computer and indoor light can darken those spots as well.”

Multiple Choice

Do people of color need to wear sunscreen?

• Yes

• No

Multiple Choice

All of the following are reasons that people of color need to use sunscreen EXCEPT

• To prevent sunburn

• To prevent wrinkles

• To prevent Vit D production

• To prevent skin cancer

• To prevent hyperpigmentation