Chapter 10: Skin, Hair, & Nails

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Welcome back to the Deep Dive.

Today, we are doing something a little different, something I am personally very excited about.

We are tackling the largest object you will ever own.

And likely the heaviest.

Exactly.

We are talking about the skin.

But not just the skin.

We're diving deep into Chapter 10, A Bait's Guide to Physical Examination and History -Taking.

This is the integumentary system.

Skin, hair, and nails.

It is a massive topic.

Quite literally, the skin accounts for, what is it, approximately 16 % of your total body weight.

Wow.

It covers nearly two square meters on an average adult.

That is wild to think about.

I mean, 16 % of me is just wrapper.

But it's not just a wrapper, is it?

Oh, not at all.

And that is really the mission of this Deep Dive today.

We want to move away from the idea that the skin is just some kind of covering.

It is an organ system.

A very active one.

Incredibly active.

It retains fluids.

It protects you from radiation and microorganisms.

It synthesizes vitamin D.

And it modulates your temperature.

But for the clinician, or for the student listening, it serves another critical purpose.

It's a screen.

A screen.

What do you mean by that?

A display screen.

Like on your phone.

The skin often displays the very first signs of internal disease.

So our goal today is to translate that visual language into clinical data.

We want to take you from just seeing a rash to actively inspecting, describing, and interpreting it.

I love that framing.

We are learning to read the body.

And we have a lot to get through to become fluent in this language.

We're going to start with the anatomy, the nuts and bolts of it all.

We'll talk about the health history.

So what questions actually unlock the diagnosis?

We're going to spend a good chunk of time on what I'm calling the grammar of dermatology, which is how to describe what you see so another doctor knows exactly what you mean.

Precision is everything in dermatology.

You can't be vague.

Absolutely.

Then we will walk through the physical exam itself.

The sequence, the techniques, how to actually do it.

We've got some special tests for things like hair loss and pressure We will wrap up with the heavy hitters.

Skin cancer screening and prevention.

It is a really comprehensive roadmap of the chapter.

So let's start at the foundation, or rather the surface.

Anatomy and physiology.

The text describes the skin as having what?

Three layers.

Break that down for us.

Right.

So structurally, you can think of the skin as having three tiers or three layers.

The most superficial layer, the one on top, is the epidermis.

That's the part we can touch.

Correct.

Now, a key thing to remember about the epidermis is that it is a vascular.

Meaning no blood vessels.

Exactly.

No blood vessels of its own.

It depends entirely on the layer below it, the dermis, for nutrition.

It's constantly waiting for nutrients to diffuse upwards.

So if I'm an epidermal cell, I'm essentially holding my breath.

I'm waiting for oxygen and nutrients to just sort of drift up from the dermis below.

That is a perfect way to put it.

And that biological constraint, that distance from the blood supply, dictates a lot of pathology.

Because that diffusion distance is limited, the cells at the very, very top, the stratum corneum, they're dead.

They have to be.

They have to be.

They're just too far from the supply line.

But that's a feature, not a bug.

Because dead cells make a better shield.

Precisely.

The best way to think of the epidermis is the brick and mortar model.

It's like a brick wall.

The bricks are the corneocytes.

Those are the dead, flattened protein cells.

And the mortar is this complex lipid matrix that holds them all together.

Okay, so when we put on moisturizer, are we fixing the bricks or the mortar?

You are usually patching the mortar.

You're adding lipids to seal the cracks so that water doesn't escape from your skin.

You're reinforcing that barrier.

Got it.

And that barrier is sitting on top of the next layer.

It is, but there's a really important junction between them.

It's called the basement membrane zone.

This is the glue holding the epidermis to the dermis.

The transition zone.

Yes.

And in a young person, this junction looks kind of like an egg crate.

It has all these deep ridges called reet ridges that interlock and lock the two layers together very tightly.

Like Velcro.

It's exactly like Velcro.

But as you age, those ridges flatten out.

The Velcro loses its grip.

So the surface area of contact drops.

It drops significantly.

And this is why, you know, if you put a piece of strong tape on an 80 -year -old's arm and then you rip it off, you might actually delaminate their skin.

You're not just pulling off hair.

No, you're literally tearing the epidermis off the dermis because that structural connection has weakened so much over time.

It explains why skin tears are so common in the elderly.

That puts skin tear in a whole new light.

It's not just a cut.

It's a structural failure of those anchor points.

It is.

Now, let's talk about the migration.

The epidermis isn't static.

It's a constant conveyor belt.

Right.

The text mentions a timeline here.

Yes.

The migration from the inner living layer, the stratum basal and stratum spinosum, to that outer dead layer takes approximately one month.

So the skin I see in the mirror today is essentially a month -old history of that migration process.

Exactly.

And that inner layer is where all the action happens.

It's where melanin and keratin are formed.

But again, it all relies on what's underneath it, the dermis.

The infrastructure layer.

Perfect term for it.

The dermis is dense, and it's vascular.

This is where the blood supply lives.

It's full of these interconnecting collagen and elastic fibers.

What's the difference in function there between collagen and elastic fibers?

So collagen gives the skin its strength, its resistance to tearing.

Elastic fibers give it recoil.

That's the ability to snap back after you stretch it.

And I assume we lose both as we age.

We do, which is why wrinkles form and skin starts to sag.

But the dermis also houses what we call the epidermal appendages.

Appendages?

That sounds like arms and legs.

Hey, yeah.

In this context, it means things like sweat glands, hair follicles, and sebaceous glands.

Even though they're made of epidermal cells, they actually dive deep into the dermal layer to anchor themselves and to get access to that rich blood supply.

And the nerves are there too, right?

That's why a deep cut hurts so much.

Correct.

That's why a paper cut, which is often just in the epidermis, might sting a little.

But a deeper cut that breaches the dermis really hurts and it bleeds.

You've hit the nerves in the vessels.

Okay.

And below the dermis, the final layer.

The third layer is the subcutaneous tissue.

This is mostly adipose tissue or fat.

It provides insulation, it's a cushion, and it stores energy.

Okay.

So we have the epidermis, dermis, and subcutaneous tissue.

Now, one of the first things you notice about skin is its color.

And the text gets really specific about the pigments involved.

It's not just one thing painting the picture, is it?

No, it's actually a blend of four different pigments, and understanding them is key to diagnosis.

First, you have melanin, that is the brownish pigment.

It is genetically determined, but as we all know, it increases with sun exposure.

It's a can.

Exactly.

Then you have carotene.

This is a yellow pigment.

It tends to hang out in the fat and in areas that are heavily carotenized, like the palms of your hands or the soles of your feet.

I feel like I've seen that, where someone's palms look a little yellowish.

It is quite common, especially if their diet is rich in carrots or other carotene -heavy foods.

It can be mistaken for jaundice, but it's not.

So how do you tell the difference?

You look at the sclera, the whites of the eyes.

In true jaundice, the eyes turn yellow.

With carotenemia, they stay white.

Ah, okay.

That's a great clinical pearl.

So we have melanin and carotene.

Then we have the blood pigments, which are crucial for assessing acute health.

We have oxyhemoglobin and deoxyhemoglobin.

Red and blue.

Essentially, yes.

Oxyhemoglobin is bright red.

It's found in the arteries and capillaries.

When you blush or when you are flushed from exercise, that is the oxyhemoglobin causing the reddening.

And a blue.

That is deoxyhemoglobin.

After the blood passes through the capillary bed and releases its oxygen to the tissues, the hemoglobin pigment becomes darker and bluer.

This is what circulates in the veins.

And this leads us to some really important clinical signs, right?

Like cyanosis.

Yes.

Cyanosis is that blue color you see in the skin or, more reliably, in the mucous membranes like the lips or under the tongue.

It indicates decreased oxygen in the blood or decreased blood flow, perhaps due to a cold environment, or something more serious like heart failure.

And the opposite would be something like pallor.

Exactly.

If you see pallor or paleness, especially in the nail beds or the conjunctiva of the eye, that can indicate anemia.

You're seeing less of that red oxyhemoglobin.

And jaundice, as you mentioned.

Jaundice is that yellowing, but it's distinct from keratin.

It results from increased bilirubin in the blood, which comes from the breakdown of hemin in red blood cells.

So just by looking at the color of someone's skin, you're already getting powerful clues about their liver function, their oxygenation, and their hemoglobin levels.

It's amazing how much information is encoded just in the color.

Let's talk about the appendages briefly before we move on.

Hair and nails.

Sure.

With hair, adults essentially have two types.

You have vellus hair, which is that short, fine, inconspicuous peach fuzz.

It's usually unpigmented.

And the other type.

Then you have terminal hair.

This is coarser, thicker, pigmented, and much more conspicuous hair.

Eyebrows and aftercubridae, axillary, and pubic hair are all classic examples.

And nails.

I always think of nails as just hard skin.

In a sense, they are.

They're composed of hardened keratin.

Their main job is to protect the distal ends of the fingers and toes.

The nail plate is the hard part, and it gets its pink color from the rich, vascular nail bed that's sitting right underneath it.

There are a few specific terms the text wants us to know here.

The lunula.

The lunula is that whitish, moon -shaped area at the base of the nail.

It represents the active matrix where new nail cells are being formed and pushed outwards.

And the cuticle.

Why is that important?

The cuticle acts as a seal, a very important one.

It protects the space between the nail fold and the nail plate from moisture and bacteria.

If that seal is broken, say, from aggressive manicuring or constant water exposure, you get an entry point for infection, a condition called paronychia.

There is a specific angle the text mentions regarding nails.

The angle between the proximal nail fold and the nail plate.

Yes, this is a key diagnostic check.

That angle should normally be less than 180 degrees.

There should be a little diamond -shaped window when you put your two index fingernails together.

What's it called when that's gone?

If it flattens outer balloons up to 180 degrees or more, we call that clubbing.

It can be a sign of chronic low oxygen levels from lung disease or heart disease or even GI issues.

It's a really important physical finding.

Okay, so anatomy is a map.

But before we even look at the patient, we have to talk to them.

Section two,

the health history.

The text says diagnosis often relies on history because lesions change.

That is a critical point.

A patient might come in and say, I had these terrible hives yesterday, but today they are completely gone.

Or the rash looked different three days ago before they put some cream on it.

If you don't get that history, you are flying blind.

So you're a detective.

Absolutely.

You need to ask about exposures, diet, cosmetics, new soaps, new detergents, chemicals at work, sunlight, recent travel.

You're always looking for the trigger.

What are the big symptoms we are listening for?

Obviously, lesions is the big bucket.

Any new growths, sores, or lumps.

But specifically, we are looking for changes in existing marks, like a mole.

That is often how skin cancer is first caught.

And then there's the sensation, itching, pruritus.

The text calls itching the most important symptom when assessing rashes.

Which feels counterintuitive.

Pain usually gets all the glory in medicine.

Why is the itch the king of dermatology?

Because the itch tells you so much.

It's the brain's way of telling you that something is irritating the skin barrier.

Or that the nerves themselves are misfiring.

We have a saying,

is it the itch that rashes or the rash that itches?

I can see that again.

The itch that rashes or the rash that itches?

It sounds like a riddle, but it's a crucial diagnostic question.

It distinguishes cause from effect.

Okay, so the rash that itches.

That's like poison ivy.

You get the rash from the plant oil, and then the rash causes the itch.

Simple.

And the itch that rashes.

That's a condition like eczema or neurodermatitis.

The patient feels an itch first, they scratch that itch, and the act of scratching creates the rash.

It damages the skin.

So the scratching itself is the cause of the lesion.

Exactly.

But the scariest scenario is the third one.

The itch with no rash.

The invisible itch.

Yes.

You have a patient, maybe 60 years old, they come in, and they are scratching their skin raw, they're losing sleep, they're miserable.

But when you examine them, aside from the scratch marks, the skin is clear.

No hives, no bites, no fungus.

That sounds like it could be psychological.

And that is the trap that clinicians often fall into.

They think it's anxiety or just dry skin.

But generalized pruridis without a primary rash is a massive warning siren for internal malignancy or systemic organ failure.

What kind of failure are we talking about?

Renal failure is a big one.

So kidney disease, uremic frost, or just high levels of waste products in the blood can cause an intense, maddening itch.

Liver disease is another one obstructive biliary disease causes bile salts to deposit in the skin.

Also, intense itching.

So the liver is failing and the skin is the alarm system.

It is.

Lymphoma is another classic cause.

Hodgkin's lymphoma often presents with a relentless itch, sometimes for months before any lymph nodes start to swell.

So if your patient says I'm itchy all over and you don't see a bug bite, you shouldn't just be reaching for the hydrocortisone.

You should be reaching for a blood draw kit.

You need to check the kidneys, the liver, the thyroid.

Wow.

So I'm itchy can actually mean check my internal organs.

That is a massive insight.

What about hair and nails in the history?

What are we asking there?

For hair loss, you want to differentiate between thinning and shedding.

Is it gradually getting less dense or is it coming out in clumps?

And if it is shedding, does it come out at the roots or is the shaft breaking halfway down?

Breaking would imply damage, right?

Like from heat or chemicals.

Exactly.

You ask about hair care practices, dyes, straighteners, heat styling.

That causes breakage.

Shedding from the root implies a systemic cycle change like telogen effluvium after a major stressor like surgery, childbirth or severe illness.

And with nails.

You're asking about changes in color or shape.

Are they turning yellow?

Are they becoming brittle?

Are they pitting?

Each of those could be a clue to something else like psoriasis or fungal infection.

Okay, let's move to section three.

This is what I'm calling the grammar of dermatology.

The text is very, very strict here.

You can't just say there's a red bump.

Red bump is useless in a medical record.

The text outlines eight specific attributes you need to describe for any lesion you find.

Let's run through them.

Number, size, color, shape, texture, primary lesion, location and configuration.

And size needs to be measured, right?

Not just big or small.

Correct.

You have to measure with a ruler in millimeters or centimeters.

Size of a quarter is okay for a patient to say, but a clinician should say 2 .5 centimeters.

Precision matters.

Let's unpack the primary lesion part.

This is the, what is it?

Of the sentence.

The text groups them into flat, raised and fluid filled.

And we need to pause on this vocabulary.

Why is the text so aggressive about us learning words like papule versus nodule?

Is it just semantics?

Oh, it's the difference between a diagnosis and a guess.

The skin has a very limited vocabulary of how it can react to an insult.

It can turn red, it can raise up, it can blister or it can scale.

That's about it.

So the specific combination of those features, the morphology is the code that tells you what's going on.

Break that down.

If I tell a dermatologist over the phone, I have a patient with a red bump, what do they picture?

Nothing, or rather everything.

It could be a mosquito bite, an acne pimple, a cyst or a deadly nodular melanoma.

Red bump is useless.

But if you say I have a patient with a five millimeter firm dome shaped erythematous papule, I instantly know it's superficial and solid.

The list of possibilities gets much smaller.

Okay, so let's start with the first category, flat.

These are non palpable.

The key is if you run your finger over it with your eyes closed, you can't feel it.

If it is small, less than one centimeter, it is a macule.

Think of a freckle or a simple flat mole.

And if I feel it, even a tiny bit.

Then it's not a picule, it's a papule.

And that distinction matters immensely because if a mole that used to be a flat macule suddenly becomes a palpable papule, if it starts to raise up, that could signify vertical growth.

That is a huge red flag for melanoma.

So the tactile part of the exam is just as important as the visual.

You have to touch the lesion to correctly name it.

100%.

What if the flat spot is big?

Then it is a patch, greater than one centimeter.

Vitiligo is a classic example of a patch, large flat areas of depigmentation.

Or suberache dermatitis can present as large pinkish patches.

Okay, so macule is small flat, patch is big flat.

Now the next category, raised, these are all palpable.

Right.

And again, size is the first differentiator.

If it's small, less than one centimeter, it is a papule.

An elevated nevus or a wart or an insect bite are all papules.

And the big version of a papule.

Is a plaque, greater than one centimeter and often described as having a flat top, like a plateau.

Psoriasis is the textbook example of a plaque.

A raised, scaly, well demarcated plaque.

Now what if it's a raise, but it feels deeper?

Like a marble or a lump under the skin?

That would be a nodule.

It's larger and deeper than a papule.

It has more of a three -dimensional quality to it.

A cyst or a lipoma would be a nodule.

It feel like a mass in the skin rather than a bump on the skin.

And then there's the wheel.

This one seems a bit different.

A wheel is unique.

It's localized dermal edema.

Think of hives or urticaria.

It's raised, but it's transient.

It comes and goes typically within 24 to 48 hours.

It's a swelling of the skin itself.

Got it.

Moving to the third category, fluid -filled.

Again, size matters.

If it's small, less than one centimeter and filled with clear fluid, it is a vesicle.

Herpes and shingles present with classic vesicles.

Little tiny blisters.

Now imagine changing that one word.

If I called in a consultant and said, my patient has papules, you might think of warts or acne.

But if I say vesicles.

The entire differential diagnosis shifts.

Suddenly, I'm not thinking about a solid growth.

I'm thinking viral.

I'm thinking herpes simplex.

I'm thinking chicken pox or shingles.

Just that one word shift solid to fluid completely changes the game.

And the large version of a vesicle.

A bulla, greater than one centimeter, also filled with clear fluid.

You see this in severe blistering disorders like bullous pymphigoid or with a severe burn or friction blister.

And what if the fluid isn't clear?

What if it's pus?

Then it is a pustule.

It's filled with purulent fluid, which is basically neutrophils and keratin debris.

Acne and folliculitis are the classic pustules.

This vocabulary is so precise.

It really does paint a picture.

If I say grouped vesicles on an erythematous base,

any dermatologist in the world immediately thinks herpes simplex.

Exactly.

And you just used another one of the key eight attributes.

Configuration.

You said grouped.

Configuration describes the pattern or arrangement of the lesions.

Let's talk about those patterns.

The text lists a few key ones.

You have linear.

Right, like poison ivy.

It creates a straight line where the plant brushed against the skin or from scratching, which we call covenerization.

Then there's annular.

Which means ring -like with central clearing.

This is the classic presentation of tinea corporis or ringworm.

It looks like a target or a ring that spreads outwards.

What about numular or discoid?

That means coin -shaped.

But unlike annular, there is no central clearing.

It's a solid coin of inflammation.

You see this in numular eczema.

And serpiginous.

That's a great word.

It is.

It means snake -like or curving.

Some fungal infections or larva migrans can have a serpiginous pattern.

And finally, dermatomal.

This one seems critically important.

Very.

It means the lesions follow a single nerve segment or a dermatome.

Herpes zoster or shingles is the prime example.

The rash wraps around the trunk or a limb, but it very strictly does not cross the midline of the body because it is following that one specific nerve root.

So if you see a blistering rash that stops perfectly at the center of the patient's back, you should immediately think dermatomal.

Precisely.

It's following the roadmap laid out by the nervous system.

It's a massive clue.

OK.

We know the words now.

Now we need to get our hands dirty, figuratively speaking.

Section four, the physical examination.

How do we set ourselves up for success here?

Preparation is absolutely key.

You cannot inspect what you cannot see.

So lighting is crucial.

Good ambient light, preferably natural light from a window, but you often need a strong artificial light source as well.

And use a magnifying glass.

Don't be afraid to get close.

The text also mentions dermoscopy.

Tell us about that.

A dermoscope is a handheld device, sort of like an otoscope for the skin.

It uses cross -polarized light and magnification to visualize pigment patterns and vascular structures deep in the epidermis and dermis.

It allows you to see things the naked eye simply cannot, which is incredibly helpful in distinguishing benign moles from malignant ones.

This is a step up from just a magnifying glass.

A big step up.

It's become the standard of care in dermatology.

And we have to talk about the gown.

We do.

The gown must open in the back.

Why is that so specific?

Why does that matter?

Because if the patient is clutching the gown closed in the front, you are never going to properly examine their back.

And the back is a very high -risk area for melanoma that patients can't see themselves, especially in men.

The patient should ideally be undressed, except for their underwear, to allow for a full body check.

But that can be intimidating for the patient.

It can be.

So communication is vital.

You must ask permission before exposing any area.

You say, I'd like to separate the gown now to look at the skin on your back.

Is that OK with you?

You narrate every step.

Respect and modesty are paramount.

And what about hygiene?

The text has an interesting point about recommending hand sanitizer over soap and water for the clinician.

Yes, that's interesting, right?

It's to prevent irritant contact dermatitis for the clinician.

If you are washing your hands with soap and water 40 or 50 times a day between patients, your own skin barriers break down.

Alcohol -based sanitizer is generally less drying and less irritating over the course of a long day.

OK, walk us through the sequence of the exam.

We start with the patient seated.

Start at the top.

You examine the hair and scalp.

You have to physically part the hair in multiple places.

Don't just look at the hairstyle.

Look at the scalp itself for scaling, redness, or lesions.

Then move to the head and neck.

Check the eyelids, inside the mouth, behind the ears.

Behind the ears, why there?

It's a very common spot for basal cell carcinomas that get missed because nobody ever looks there.

Sun hits the tops of the ears.

Makes sense.

Then down to the upper body.

Right, upper back, shoulders, arms, hands.

You need to inspect and palpate the fingernails.

Look at the color, the shape.

Then you examine the chest and abdomen.

The patient can help here by lowering or raising the gown themselves, which gives them a sense of control.

And the legs.

Anterior thighs, legs, and feet.

And you must, must, must check between the toes.

Why the emphasis on between the toes?

It's a prime hiding spot for tineaeopeties, which is athlete's foot.

It's a place where infections can start in patients with diabetes.

And tragically, it's a hiding spot for acrolintigenous melanoma, a very dangerous type of skin cancer.

It's a dark, moist environment that people rarely inspect themselves.

Okay, then we stand the patient up.

That's right.

This is for the lower back and the posterior thighs and legs.

If needed, you also check the buttocks.

Now, the text mentions the integrated skin exam.

I think this is such a great, practical time saver tip for busy students or clinicians.

It is the most practical way to do this in a real world setting.

You don't always have time for a dedicated 20 -minute skin -only exam.

So when you are listening to the patient's lungs, you are looking at the skin on their back.

When you are checking their abdomen for tenderness, you are also looking for moles or rashes.

You integrate the skin check into the rest of the physical exam.

You're already there, so you might as well look.

Exactly.

It saves time and it helps you catch those hidden lesions without making the patient feel like they are under a microscope for an uncomfortable amount of time.

Let's move to section five.

Special techniques.

Sometimes just looking isn't enough.

We have some specific tests for hair loss.

Right.

When a patient complains of hair loss, we need to know the mechanism.

Is it falling out or breaking off?

We use the pull test and the tub test to figure that out.

What's the difference between them?

The pull test checks for shedding from the roots.

You grasp a group of about 50 to 60 hairs between your thumb and forefinger, and you pull firmly but gently away from the scalp.

If more than, say, five or six hairs come out and you see the little white telogen bulbs at the end, it suggests telogen effluvium, which is an active shedding process from the roots.

And the tug test.

The tug test checks for fragility of the hair shaft itself.

You hold a group of hairs and you pull along the shaft away from the root.

If the hairs break mid -shaft, that suggests the hair itself is fragile, likely from chemical damage, heat styling, or a genetic hair disorder.

So, pull for roots, tug for breakage.

That's a very clear distinction.

Now, a very serious topic.

The bedbound patient and pressure injuries.

This is critical for anyone working in a hospital or a long -term care facility.

Patients who are emaciated, elderly, or have neurologic impairment are at extremely high risk.

It's all about blood flow, right?

It's entirely about blood flow.

Sustained, compression -like, lying in one spot for too long, squeezes the capillary shut and obliterates blood flow to the skin and underlying tissue.

This happens most often over bony prominences.

Like the sacrum.

The sacrum, the buttocks, the greater trochanters on the hips, the heels.

You have to physically roll the patient over to see their back and sacrum.

You can't just glance.

And we have a staging system for this.

The text notes it was revised, so we need to be precise here.

Yes, there are stages one through four plus two special categories that are important to know.

Let's go through them.

Stage one.

In stage one, the skin is still intact, but there's non -blanchable erythema.

That means if you press on the red spot, it stays red.

It doesn't turn white and then pink again.

That's the first sign that the tissue is in distress.

Stage two.

Now we have actual skin loss.

It's a partial thickness loss, so the dermis is exposed.

It often looks like a shallow open sore or a blister that has ruptured.

This is full thickness skin loss.

You can now see the subcutaneous fat, the adipose tissue in the base of the ulcer, but you can't see muscle or bone yet.

And stage four.

Stage four is full thickness loss, where you can see exposed or directly palpable muscle, bone, or tendon.

These are deep, very serious wounds that are prone to infection.

Then there are the tricky ones.

Unstageable.

What does that mean?

That's when the base of the ulcer is covered by slow or escher, which is dead tissue that looks yellow, tan, or black.

You can't tell how deep the wound is because your view is blocked by this debris, so you can't stage it until a surgeon or wound care specialist cleans that out.

And the last one, deep tissue injury.

This one is subtle, but dangerous.

It presents as a non -blanchable deep red, maroon, or purple discoloration.

It might look like a deep bruise, but it indicates significant damage to the underlying soft tissue, even if the skin surface is still intact.

It can progress very rapidly to a stage three or four ulcer.

These are so vital to catch early because they can progress incredibly fast.

Speed is everything with pressure injuries.

Stage one is a warning light.

Stage four is a full blown crisis.

Let's transition to section six, health promotion and counseling.

We are talking about skin cancer.

The statistics are sobering.

Skin cancers are the most common cancers in the United States.

Roughly one in five Americans will develop some form of skin cancer in their lifetime.

That is a staggering number.

It's hard to even process.

It is.

We primarily deal with three main types.

Basal cell carcinoma, BCC, is by far the most common.

It's rarely fatal, but it can be locally destructive and disfiguring if not treated.

Then you have squamous cell carcinoma, SEC, which is the second most common.

And then the big one, melanoma.

Melanoma is the least common, accounting for only about 1 % of all skin cancers, but it is by far the most lethal.

It is responsible for the majority of skin cancer deaths.

What are the risk factors we need to be warning our patients about?

Without a doubt, UV radiation is the strongest, most modifiable risk factor.

That means sun exposure and tanning beds.

And it's not just about getting a tan, intermittent, severe exposure, like those blistering sunburns you got as a child on vacation, is particularly harmful.

The text says a specific stat about indoor tanning that really blew my mind.

Indoor tanning increases your risk of developing melanoma by 75 % if you start before the age of 35.

75%.

That's not a small number.

It's a massive increase for a purely voluntary cosmetic activity.

It really should be on a warning label on every tanning bed.

So how do we screen for this?

We all learn the ABCDE rule in school.

Asymmetry, border, color, diameter, evolution.

Is it enough?

It's necessary, but it's not always sufficient.

It's the baseline, and it's a great tool.

The problem with the ABCDEs is that they are designed primarily to detect superficial spreading melanoma.

That's the most common type, the one that grows outwards like a puddle before it grows down.

Okay, let's run through the basics first, though, just as a refresher.

A is four.

Asymmetry.

If you draw a line through the middle of the mole, one side doesn't match the other.

Border.

Is it irregular, ragged, notched, or blurred?

The nine moles usually have smooth, even borders.

Color.

Variation is a bad sign.

If you see shades of blue, black, white, and red all within one lesion, that is a major warning sign.

Diameter.

Generally, anything greater than six millimeters, which is about the size of a pencil eraser, is considered suspicious, though it's important to remember that early melanomas can definitely be smaller.

And E, which might be the most important one.

I agree.

Evolution.

This is arguably the most sensitive criterion.

Is the mole changing?

Is it growing rapidly in size, changing shape, or developing new symptoms like bleeding or itching?

A mole that changes is a mole that needs to be checked by a professional.

Now, you mentioned this might not be enough.

What does the classic ABCDE rule miss?

It often misses nodular melanoma.

This is the really scary one.

It tends to grow vertically down into the tissue right from the start, rather than spreading out across the surface.

These can be perfectly symmetrical.

They can have a smooth border.

They can be one solid color like black or pink.

So they can pass the A, B, and C tests with flying colors.

They do.

And that's how they kill people.

They get dismissed as a blood blister or a pimple that just won't heal.

So for these, we use the EFG rule as an add -on.

EFG?

What's that?

Elevated.

Firm to the touch.

And growing progressively over several weeks to months.

If you have a new firm bump that is getting bigger, that is a dermatologic emergency, even if it's a perfect circle.

That firm part is interesting.

Why firm?

Because it's a dense collection of malignant cells packed together.

A benign cyst might be squishy.

A skin tag is soft.

Nodular melanoma often feels hard, like a small pebble under the skin.

The text also mentions the ugly duckling sign.

I find this one very intuitive.

It's probably the best tool for the non -dermatologist.

The concept is that most people make moles that look like they're other moles.

They have a signature mole type.

If a patient has 50 moles, and they are all small, light brown, and flat, but there's one that is black, large, and raised, that's the ugly duckling.

It stands out from the rest.

It's the outlier.

Right.

And conversely, if a patient has a back full of weird, large, irregular moles, that might just be their normal, what we call, dysplastic nevado.

But if they have one perfectly small, round pink dot in the middle of all those chaotic moles,

that might be the ugly duckling in their case.

It's the one that doesn't fit the patient's personal pattern.

So you're not just comparing the mole to a textbook picture.

You're comparing the mole to its neighbors on that same person.

Context is everything.

Pattern recognition isn't just looking at the lesion in isolation.

It's looking at the whole canvas.

Okay.

Let's talk prevention counseling.

What are the key points we need to tell our patients?

It's pretty straightforward.

Avoid midday sun when UV rays are strongest, usually between 10 a .m.

and 4 p .m.

Wear protective clothing, long sleeves, pants, and wide -brimmed hats are great.

And of course, sunscreen.

What are the specs for sunscreen?

Does any kind of work?

No.

You want at least SPF 30.

It needs to be broad spectrum, which means it blocks both UVA and UVB rays, and it should be water resistant.

But the biggest mistake people make is application.

Not using enough.

That and not reapplying.

You need to apply it generously to all exposed skin about 15 minutes before you go out.

And you must reapply it at least every two hours, or more often if you're swimming or sweating a lot.

And self -exams are a big part of this too, right?

They're essential.

We need to teach patients how to use a full -length mirror and a handheld mirror to systematically check their entire body.

Check the front, back sides.

And you have to teach them to check the hidden areas, the soles of their feet, between their toes, their scalp, their buttocks.

It sounds a little awkward, but it absolutely saves lives.

It does.

Early detection is everything with melanoma.

We are coming toward the end, but we need to talk about documentation.

Section seven.

You mentioned earlier that red bump is bad documentation.

Give us an example of what good documentation looks like.

The text gives a fantastic comparison.

Red rash on back.

Multiple five millimeter to two centimeters tanned to brown,

oval stuck on flat popped varicose plaques on the back, and abdomen in no specific configuration.

I can visualize that second one perfectly.

It sounds exactly like seborrhea keratosis.

Exactly right.

The description leads you to the diagnosis.

If you write red rash, you are forcing the next doctor who sees that patient to start from scratch.

If you write the detailed description, you are giving them a huge head start and ensuring continuity of care.

And finally, I wanna end with a thought that really stuck with me from reading this chapter.

The iceberg concept of skin findings.

Yes.

The idea that what you see on the surface of the skin is often just the tip of the iceberg.

The skin is the external window to internal health.

A simple change in nail color like pallor or clubbing can unlock a diagnosis of anemia or lung disease.

A patch of dry, intensely itchy skin might be the first clue to underlying kidney failure.

That purple rash on the legs might be vasculitis from an autoimmune disease.

It really emphasizes why we do all this.

We aren't just looking at the surface.

We are reading the body's dashboard for warning lights.

And that is why the integumentary exam is so powerful.

It is non -invasive.

It is immediate.

And if you know the language, if you know your matulas from your papules and your annular from your dermatomal and your ABCDs, it offers incredible insight into the patient's overall wellbeing.

So what does this all mean for you, the listener, the learner?

It means take that extra minute in the exam room.

Look at the nails, check between the toes.

Don't dismiss the itch and practice your descriptive adjectives.

And don't be afraid to measure.

Get a small roller for your pocket.

Be specific.

It will make you a better clinician.

We hope this deep dive helps you feel a little more confident, a little more curious the next time you approach a patient.

And maybe helps you appreciate the incredible complex organ that is the skin you live in every day.

Thanks for listening.

This has been a production of the Last Minute Lecture Team.

We'll see you on the next deep dive.