Time To Read
Date Last Modified
MODULE 5:
Integumentary System
PART 5 OF 7
Two skin diagnoses, opposite behaviors: psoriasis (thick, fast, scaly) and eczema (thin, leaky, raw). Same patient, same decade.
Slide 1 Transcript
PATIENT CHART
STINA
Grad student · recurrent fevers, pain & swelling since childhood
THIS PART
Ages 3-35
PRESENTING WITH
Variable skinThe body’s largest organ, providing protection and regulation. conditions
ACTION TAKEN
Dermatological evaluation
DIAGNOSIS
Sweet Syndrome
CHART CLUES
COLLECTED AS YOU GO
Post-Streptococcal Guttate Psoriasis
Concurrent Eczema + Sterile Pustulosis
Sweet Syndrome — Acute Febrile Neutrophilic Dermatosis
Inflammatory Cutaneous Vasculopathy
?
?
?
Put your money down: Psoriasis and eczema in one patient — aren’t those opposites?
Bet before the belt runs. Stina once asked how she could have both psoriasis and eczema — weren’t they opposites? — and was told she was just ‘sensitive-skinned.’ Two quick fact-checks on epidermal turnover; then the ask: are her two diagnoses truly opposite diseases — or two failures of one conveyor belt?
Pick the answer you believe now. We’ll come back to it later!
Some People Are Just Sensitive-Skinned
Stina once asked a dermatologist how she could have both psoriasis and eczema — weren’t they opposites? He said some people are just “sensitive-skinned.” The real answer is more satisfying and more precise, and it lives in the timing of a single conveyor belt. Her plaques and her weeping patches are two different breakdowns of the same assembly line.
Your Skin’s Monthly Makeover
Normal epidermal turnover is about 28 days — a full makeover every month.
Slide 2 Transcript
Cash out the clip
Single Choice: About how long does normal epidermal turnover take?
Psoriasis — The Hyperactive Factory
What happens when the belt sprints — cellsThe basic structural and functional units of life. arrive in 3–4 days, unfinished.
Slide 3 Transcript
Cash out the clip
Drag the Words: Drop the facts about the psoriatic (sped-up) belt.
One Belt, Two Ways to Break It
Run the epidermal belt at its normal speed and a keratinocyte takes about twenty-eight days to climb from the stratum basaleThe deepest layer of the epidermis, where new skin cells are formed., mature, die into a flat protective scale, and shed. There are two very different ways to wreck that process. You can run the belt too fast: in psoriasis, cells reach the surface in three or four days, arrive unfinished, fail to build a proper barrier, and heap up into thick silvery plaques — a speed defect. Or you can run it at roughly normal speed but assemble a defective product: in eczema, the lipid mortar and tight junctions are faulty, so the finished barrier leaks waterThe universal solvent essential for life. out and lets irritants in — a quality defect.
Eczema — The Quality-Control Disaster
Normal speed, defective product — the barrier leaks and irritants pour in.
Slide 4 Transcript
Cash out the clip
Fill in the Blanks: Fill in why eczema is a quality (barrier) defect.
Speed vs Quality
Same skin, two different failures — one belt, two ways to break it.
Slide 5 Transcript
Cash out the clip
Mark the Words: Mark which features belong to the speed defect vs the quality defect.
Two Readings of a Single Dial
Speed problem versus quality problem — opposite-looking skin, but both sit downstream of the same inflammatory signaling. That is why one patient can carry both at once with no contradiction at all. Once you can see the belt, Stina’s lifelong “how do I have both?” stops being a paradox and becomes something much simpler: two readings of a single dial, turned by the same hand. The dermatologist wasn’t wrong that her skin was unusual; he was just describing the dial instead of the hand on it.
FINDING!
Two Opposite-Looking Dermatoses
Concrete reconciliation of her chart: psoriasis (thick, fast, scaly) and eczema (thin, leaky, raw) in the same patient and decade are not a contradiction. Run the keratinocyte belt at normal speed and a cell takes ~28 days to mature and shed; psoriasis runs it at 3–4 days (cells arrive unfinished and pile into plaques), while eczema keeps normal speed but builds a defective, leaky product (faulty barrier lipidsOrganic molecules including fats, oils, and steroids. and tight junctions). Chart entry: a speed defect and a quality defect of the same belt — two readings of one dial, both downstream of the same inflammatory signal.
Confirm or refute your bet: Psoriasis and eczema in one patient — aren’t those opposites?
Having timed the keratinocyte belt, return to the bet. Run at normal speed a cell takes ~28 days; psoriasis runs it at 3–4 days (cells arrive unfinished, pile into plaques), while eczema keeps normal speed but builds a defective, leaky product. Speed versus quality, both downstream of the same inflammatory signal.
Slide 7 Transcript
NEXT PART
A racing or leaking belt is bad enough. But what happens when inflamed skin is actually injured — a cut, a scrape, a biopsy site? Stina’s wounds have a habit of refusing to close.
PREVIOUS
QUICK QUESTIONS
QUICK QUESTIONS
PREVIOUS
Hop to:
← Familial Mediterranean Fever — case home
All pages for Module 5 — The Integumentary System
5.0 Module Overview
5.1 The Rash Nobody Noticed
5.2 The Barrier Breaking Down
5.3 The Fever Rash
5.4 Red Feet & Mottled Shins
5.5 The Epidermal Conveyor Belt
5.6 Wounds That Won’t Heal
5.7 Inside the Skin’s Inflammation
5.8 Conclusion and Assessment
5.9 The evidence behind Stina’s skin
All Modules
- Anatomical Language, Membranes & Homeostasis
- Just Enough Chemistry
- The Cell & Its Transport
- Making Cells & Proteins
- The Integumentary System
- The Skeletal System
- The Muscular System
- Nervous Tissue & the Senses
- The Spinal Cord
- The Brain & the Blood–Brain Barrier
- The Autonomic Nervous System
- Special Senses (in developmentThe process of growth and differentiation.)
- The Endocrine System
- Blood
- The Heart
- Blood Vessels
- The Digestive System
- The Respiratory System
- The Urinary System
- Fluids, Electrolytes & Acid–Base Balance
- The Reproductive System
- The Immune System
List of terms
- skin
- cells
- stratum basale
- water
- lipids
- development