Nursing Field Notes / Integumentary · Skin Infections & Inflammatory Conditions · Pathophysiology Course

🩹 SKIN INFECTION & INFLAMMATION SETNG-147 Cellulitis NG-209 Impetigo NG-067 Tinea NG-202 HSV & Shingles NG-225 Psoriasis

HSV & Shingles ⚡

Herpes simplex & herpes zoster — the viruses that live in your nerves

NG-202 INTEGUMENTARY · VIRAL ADHD-friendly visual edition

Shingles is reactivation of the varicella-zoster virus — chickenpox that has been asleep in a nerve ganglion for decades. When immunity dips it travels back down the nerve and blisters the skin that nerve supplies: one dermatome, one side, stopping at the midline, with burning pain 2–3 days before the rash. Herpes simplex does the same trick on the lip or genitals. All of them are treated with the "-cyclovir" family, started within 72 hours — and the contagion rule is the one students get wrong: a person without varicella immunity catches chickenpox, not shingles.

📄 Simple Nursing original — opens in Drive →

⚡ ONE band · ONE sideShingles follows a single dermatome and stops at the midline. That is the whole diagnosis in one glance.

😣 Pain comes FIRSTBurning, tingling or stabbing 2–3 days before any rash — the nerve is inflamed before the skin is.

⏱️ Antiviral within 72 hAcyclovir · valacyclovir · famciclovir — start as early as possible after the rash appears.

🦠 You catch CHICKENPOXNot shingles. A person without varicella immunity exposed to the blister fluid develops chickenpox.

🧬

THE SKIN MODEL

STEP 0 · LEARN THIS ONCE

Same skin drawing as every page in this set — this time the disease arrives down the nerve instead of through the surface.

🔬 Skin cutaway — the only one that comes from the INSIDE

DEPTH = THE ANSWER Bacteria and fungi come in from outside. This virus lives in a sensory nerve ganglion and travels down the axon into the epidermis it supplies. That is why the rash is banded, one-sided and painful before it is visible.

virus particles inflamed sensory nerve intra-epidermal vesicle erythematous base

🧠 "Grouped vesicles on a red base" is the sentence that means herpes family — cold sore, genital herpes or shingles.

📖 Lesion vocabulary — this is a vesicle disease

Vesicle → pustule → crust, all in a band. Highlighted below.

🧠 Scattered = chickenpox. Clustered in a band = shingles. Clustered on the lip = cold sore.

🦠

PATHO & CAUSES

STEP 1 · WHY IT HAPPENS

An old virus, a tired immune system, and a nerve that remembers exactly where it goes.

🧠 The one-sentence definition

Shingles (herpes zoster) is reactivation of the varicella-zoster virus — the virus that caused chickenpox — from a sensory nerve ganglion, producing a painful blistering rash in the dermatome that nerve supplies.

Herpes simplex (HSV-1 / HSV-2) behaves the same way: it hides in ganglia and reactivates as grouped vesicles in the same spot each time.

🧠 "Chickenpox once, shingles later." No chickenpox (or vaccine virus) = no shingles.

⚙️ Mechanism, step by step

Chickenpox in childhood

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Virus travels UP sensory nerves and goes dormant in the dorsal root ganglia

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Years later, cell-mediated immunity drops

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Virus reactivates and travels DOWN the axon

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Nerve inflammation = burning pain FIRST

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Grouped vesicles appear in that ONE dermatome

🧠 It is an "opportunistic" reactivation — the virus waits until your defenses are down before it attacks.

🧬 Where it comes from — chickenpox that never left

🧠 The ganglion is the hotel. The virus checks in after chickenpox and checks out when your immune system stops watching the door.

⭐ Risk factors — "defenses are down"

Age — risk rises sharply after 50, as VZV-specific immunity wanes
Immunosuppressive drugs — corticosteroids, chemotherapy, transplant drugs, biologics
Cancer, especially hematological; HIV; other immunodeficiency
Another active infection (e.g. pneumonia) occupying the immune system
Major physical or emotional stress, fatigue, poor nutrition
Surgery, trauma, radiation

🧠 "Old, ill, stressed, suppressed." Four words, all the risk factors.

🧪 Bug → drug: the rule that runs this whole set

🧠 Virus → "-cyclovir". Antivirals suppress, they do not cure — the virus stays in the ganglion for life.

🔎

CLUES

STEP 2 · WHAT YOU SEE

Pain first, then a one-sided band of grouped blisters that refuses to cross the midline.

👀 Signs & symptoms

Prodrome: burning, tingling, itching, numbness or stabbing pain in one strip of skin, 2–3 days before the rash
Rash: red papules → grouped vesicles on an erythematous base → pustules → crusts
Unilateral, following one dermatome, most often the trunk (thoracic) — it stops at the midline
Paraesthesia — burning, numbness, tingling, hypersensitivity to touch
Low-grade fever < 38 °C / 100.4 °F, headache, malaise, fatigue
Itching as it crusts

🧠 "Pain, then band, then blisters." In that order, every time.

🩺 How it is diagnosed

Clinical — the dermatomal pattern plus grouped vesicles is usually enough
PCR / viral swab of vesicle fluid if the picture is unclear or the patient is immunocompromised
A direct fluorescent antibody test may be used where available
Consider testing for immunosuppression (including HIV) in a young patient with shingles
Ophthalmology review without delay if the eye or nose tip is involved

🧠 Shingles in a young adult is a question, not just a diagnosis — why are their defenses down?

🗺️ Dermatomes — why the rash stops at the midline

🧠 T4 nipple, T10 umbilicus. Two landmarks that show up in exams over and over.

⏱️ The timeline — and the two clocks you are watching

🧠 Clock 1 = 72 hours for the drug. Clock 2 = crusted over for the contagion.

🚨 Shingles on the face — the two emergencies

🧠 "Nose tip = eye trip." Lesions on the tip of the nose (Hutchinson's sign) mean the eye is at high risk — urgent ophthalmology.

📉 Postherpetic neuralgia — the commonest complication

🧠 The rash is temporary; the nerve damage may not be. Treat the pain aggressively and early — that is the prevention.

🩺

CARE

STEP 3 · WHAT YOU DO

Antiviral early, pain controlled properly, and everyone around the patient protected.

🦠 Who can catch what — the rule everyone gets wrong

🧠 Shingles gives chickenpox, not shingles. Say that sentence out loud until it sticks.

💊 Antivirals — the "-cyclovir" family

Acyclovir · valacyclovir · famciclovir
Start as early as possible, ideally within 72 h of the rash appearing
They shorten the illness and reduce the risk of postherpetic neuralgia — they do not eradicate the virus
Encourage fluids — adequate hydration matters, especially with IV acyclovir, which can affect the kidneys
Give doses on time; monitor renal function as prescribed
For HSV, the same drugs are used episodically or as daily suppression

🧠 "-cyclovir = virus." And early beats perfect — a dose today is worth more than the ideal dose in a week.

🛡️ Precautions — get this right

Localized shingles in an immunocompetent patient: standard + contact precautions; cover the lesions with a dressing
Disseminated zoster, or zoster in an immunocompromised patient: airborne + contact precautions — negative-pressure room until lesions are crusted
Chickenpox (varicella): always airborne + contact
Staff and visitors must be immune — non-immune, pregnant or immunocompromised people should not care for or visit the patient
Keep away from newborns, pregnant people without immunity, and the immunosuppressed
Precautions continue until all lesions are crusted

🧠 "Covered and contained = contact. Spread out or immunosuppressed = airborne."

😖 Pain — treat it like nerve pain, not a scrape

Assess it properly and regularly — this pain is frequently under-treated
Neuropathic agents: gabapentin or pregabalin, tricyclic antidepressants
Topical: lidocaine patch or gel; capsaicin (only on intact, healed skin)
Analgesics as prescribed; opioids may be needed short-term for severe acute pain
Cool compresses, calamine, colloidal oatmeal baths for comfort
Loose cotton clothing — even fabric can hurt (allodynia); a bed cradle keeps sheets off the skin

🧠 Plain acetaminophen/NSAIDs alone rarely touch nerve pain. Ask for the neuropathic agent.

✅ Skin & comfort care

Keep lesions clean, dry and COVERED with a non-adherent dressing
Do not rupture the blisters — the fluid is infectious and the skin is a barrier
Keep nails short; discourage scratching (secondary bacterial infection risk)
Watch for secondary infection: increasing pain, spreading redness, pus, fever
Hand hygiene before and after all contact; gloves for lesion care
Support rest, nutrition and fluids — the immune system needs them
Acknowledge the emotional load: the pain is exhausting and often invisible to others

🧠 Cover the rash and you have cut the transmission risk enormously.

💉 Prevention — vaccination

Recombinant zoster vaccine (Shingrix) — 2 doses, recommended for adults 50 years and older, and for immunocompromised adults 19+ per current guidance
It is recommended even if the person has already had shingles or does not remember having chickenpox
It is not a live vaccine; expect a sore arm, tiredness or aches for a day or two — that is a normal response
Varicella (chickenpox) vaccine in childhood prevents the primary infection in the first place
Vaccination is the most reliable way to lower the risk of shingles and of postherpetic neuralgia (starting the antiviral early also lowers it)

🧠 "50 and over, two doses." The exam loves a vaccine-teaching answer.

❌ Never do these

Never let a non-immune, pregnant or immunocompromised person care for or visit the patient.
Never break the blisters — the fluid is loaded with live virus.
Never treat facial shingles as routine; ask about the eye every time.
Never delay the antiviral waiting for a test result.
Never tell a patient shingles is "caught" from someone else's shingles — it comes from their own dormant virus.

🧠 Don't pop it, don't delay it, don't expose the vulnerable.

🔀

TELL THEM APART

STEP 4 · THE REAL EXAM SKILL

One band that stops at the midline is shingles. Everything else is something else.

🗺️ Where each one shows up

🧠 One band, one side, stops at the midline. No other rash on this page does that.

🧬 Three herpesviruses, three patterns

	HSV-1	HSV-2	VZV (shingles)
Classic site	Lip border, mouth	Genital area	One dermatome, often trunk
Pattern	Small recurring cluster	Painful grouped ulcers	Unilateral band, stops at midline
Latent in	Trigeminal ganglion	Sacral ganglia	Dorsal root ganglia
Recurs?	Often, same spot	Often, decreasing over time	Usually once, can recur
Treatment	All three: the "-cyclovir" family — acyclovir, valacyclovir, famciclovir

🧠 Same family, same drugs, different postcode.

📊 Shingles vs chickenpox

	SHINGLES	CHICKENPOX
Which event	Reactivation	First infection
Spread	One dermatome, one side	All over the body
Age	Usually older adults	Usually children
Pain	Severe, comes first	Itch > pain
Precautions	Contact (airborne if disseminated / immunocompromised)	Airborne + contact

🧠 Same virus, two chapters.

⭐ NCLEX traps

A contact does not "get shingles" — a non-immune contact gets chickenpox.
The patient is contagious until every lesion is crusted, not until the pain stops.
Antiviral within 72 h of rash onset — do not pick "wait for the culture."
Localized, covered shingles in a well patient = contact precautions; disseminated or immunocompromised = airborne.
Pain before a rash in one strip of skin is shingles until proven otherwise.
Lesions on the nose tip → the eye is at risk → urgent referral.
Shingles pain is neuropathic — gabapentin-type drugs, not just acetaminophen.

🧠 If the option says "cover the lesions" or "until all lesions have crusted", it is usually right.

🧠 One-line contrasts

Shingles vs cellulitis — blistered band with burning nerve pain vs diffuse hot red swelling
Shingles vs contact dermatitis — dermatomal vs shaped like whatever touched the skin
Shingles vs impetigo — clustered vesicles on a red base vs honey crust
Shingles vs tinea — painful band vs itchy ring
HSV vs impetigo — recurs in the same spot after tingling vs new golden crusts anywhere

🧠 Burning band = virus. Hot swelling = bacteria. Itchy ring = fungus.

⚡

QUICK RECALL

SAY IT OUT LOUD

⚡ One dermatome, one sideStops at the midline. Grouped vesicles on a red base.

😣 Pain 2–3 days firstBurning/tingling before any rash. Treat as NEUROPATHIC pain.

⏱️ "-cyclovir" within 72 hShortens it and lowers postherpetic neuralgia risk.

🦠 Contagious till crustedA non-immune contact gets CHICKENPOX. Cover the lesions.

🎯 Cover & check — 10 rapid-fire questions

Q1: What causes shingles?

Reactivation of varicella-zoster virus — the chickenpox virus — from a sensory nerve ganglion where it has been dormant since the childhood infection.

Q2: Describe the rash in one sentence.

Grouped vesicles on an erythematous base, unilateral, following a single dermatome, and stopping at the midline.

Q3: What comes before the rash, and why does it matter?

Burning, tingling, itching or stabbing pain in that strip of skin, 2–3 days earlier, because the nerve is inflamed before the skin blisters. It is often misdiagnosed as cardiac, renal or musculoskeletal pain at this stage.

Q4: A visitor has never had chickenpox. What can they catch, and what can't they?

They can catch varicella-zoster virus from the blister fluid and develop CHICKENPOX. They cannot "catch shingles" — shingles only comes from a person's own dormant virus.

Q5: When is the patient contagious?

From when the vesicles appear until every lesion has crusted over — typically about 7–10 days. Not contagious during the prodrome, and not once fully crusted.

Q6: What precautions do you use?

Localized zoster in an immunocompetent patient: standard plus contact precautions, with the lesions covered. Disseminated zoster, or zoster in an immunocompromised patient: airborne plus contact precautions in a negative-pressure room until all lesions crust. Chickenpox: always airborne plus contact.

Q7: What is the antiviral window and which drugs?

Start as early as possible, ideally within 72 hours of the rash appearing. Acyclovir, valacyclovir or famciclovir. They shorten the course and reduce postherpetic neuralgia risk; they do not eradicate the virus.

Q8: What is postherpetic neuralgia and how is it treated?

Nerve pain that persists after the rash has healed, sometimes for months. Risk rises with age. Treated as neuropathic pain — gabapentin or pregabalin, tricyclics, topical lidocaine or capsaicin — not simple analgesics alone.

Q9: A patient has shingles on the forehead with vesicles on the tip of the nose. Why is this urgent?

Hutchinson's sign — the nasociliary branch of V1 is involved, so the eye is at high risk. Herpes zoster ophthalmicus can scar the cornea and cause permanent vision loss. It needs urgent ophthalmology review and prompt antiviral therapy.

Q10: Who should be offered the shingles vaccine?

Recombinant zoster vaccine, two doses, for adults 50 and over and for immunocompromised adults 19 and over per current guidance — including people who have already had shingles or who do not remember having chickenpox.