Browse categories and answer follow-up questions to refine your symptom profile.
Approach to the Critical Patient
Immediate threats and isolation
High risk complications triage
Ophthalmic involvement
Eye pain
Vision change
Vesicles on nose
Neurologic involvement
Altered mental status
New focal deficit
Meningismus
Disseminated infection
More than 20 lesions outside primary dermatome
Multiple noncontiguous dermatomes
Immunocompromised host
Transplant
Hematologic malignancy
High dose steroids
Infection control
Standard precautions
Cover lesions
Hand hygiene
Airborne plus contact precautions if disseminated or immunocompromised
Negative pressure room if available
N95 for staff
Time critical consultations and escalation
Escalation triggers
Immediate ophthalmology if suspected herpes zoster ophthalmicus
Eye symptoms
Hutchinson sign
Immediate neurology or infectious diseases if CNS involvement
Encephalitis concern
Myelitis concern
Admission pathway if severe pain or inability to tolerate oral therapy
Intractable pain
Persistent vomiting
Early treatment priorities
Antiviral timing
Best benefit within 72 hours of rash onset
Reduced new lesion formation
Shorter duration of acute pain
Consider beyond 72 hours if ongoing new lesions or high risk
Immunocompromised
Ophthalmic involvement
Neurologic complications
Analgesia first hour
Multimodal pain control
Acetaminophen
NSAID if appropriate
Neuropathic agent if moderate to severe pain
History
Presenting pattern and timeline
Symptom chronology
Dermatomal pain or dysesthesia
Burning
Allodynia
Rash onset time
Hours since first vesicle
New lesions ongoing
Prodrome features
Localized pain before rash
1 to 5 days typical
Pitfall mimic myocardial infarction or abdominal pathology
Systemic symptoms
Fever
Malaise
Risk factors and prior immunity
Host risk profile
Age 50 years or older
Higher postherpetic neuralgia risk
Higher complication risk
Immunocompromised state
HIV
Cancer chemotherapy
Biologic therapy
Varicella history
Prior chickenpox
Typical prerequisite for reactivation
Varicella vaccine history
Breakthrough possible
Zoster vaccination history
Recombinant zoster vaccine series
Lower incidence
Breakthrough still possible
Red flag symptoms
Eye and face symptoms
Periorbital rash
V1 distribution
Tip of nose lesion
Vision change
Blurred vision
Photophobia
Neurologic symptoms
Headache severe
Meningitis concern
Encephalitis concern
Weakness
Segmental paresis
Myelitis concern
Dissemination symptoms
Dyspnea
Pneumonitis concern
Chest pain
Cardiac or pulmonary mimic and complication screen
Physical Exam
Skin and mucosal exam
Rash distribution
Unilateral dermatomal vesicles on erythematous base
Thoracic most common
Cranial nerve dermatomes possible
Crossing midline
Consider disseminated
Consider alternate diagnosis
Lesion stage
Macules to papules to vesicles
New vesicles suggest active replication
Crusted lesions suggest later stage
Secondary bacterial infection features
Honey crusting
Purulence
Ocular and cranial nerve screening
Eye assessment
Visual acuity
Baseline compare eyes
Any reduction as urgent sign
Conjunctival injection
Keratitis risk
Uveitis risk
Fluorescein staining if available
Dendritiform lesions
Pseudodendrites
Cranial nerve findings
Facial nerve palsy
Ramsay Hunt syndrome consideration
Otalgia association
Vesicles in ear canal
Ramsay Hunt syndrome marker
Neurologic and systemic assessment
Neurologic screen
Mental status
Encephalitis concern
Medication adverse effect screen
Motor strength focal
Segmental zoster paresis
Stroke mimic
Vital signs
Fever
Dissemination risk
Secondary infection risk
Hemodynamic instability
Alternate diagnosis
Sepsis from superinfection
Differential Diagnosis
Vesicular and dermatomal mimics
Key dermatologic mimics
Herpes simplex infection
Recurrent grouped vesicles
Non dermatomal common
Contact dermatitis
Itchy
Exposure pattern
Bullous impetigo
Staphylococcal
Honey crust
Neuropathic and pain mimics
Acute coronary syndrome
Chest dermatomal pain prodrome
No rash early
Renal colic
Flank dermatomal pain prodrome
No rash early
Serious alternate diagnoses
Life threatening differentials
Necrotizing soft tissue infection
Pain out of proportion
Rapid progression
Meningitis or encephalitis non VZV
Fever
Altered mental status
Immunocompromised rash differentials
Disseminated HSV
Widespread vesicles
Mucosal involvement
Drug eruption
Morbilliform pattern
Systemic involvement
Medical coding anchors
ICD-10 and SNOMED CT mapping
ICD-10 B02.9 zoster without complications
SNOMED CT herpes zoster
Dermatomal vesicular eruption
ICD-10 B02.3 zoster ophthalmicus
SNOMED CT herpes zoster ophthalmicus
Trigeminal V1 involvement
ICD-10 B02.2 zoster with nervous system complications
SNOMED CT zoster meningitis
SNOMED CT zoster encephalitis
Laboratory Tests
Routine labs not required for uncomplicated cases
Baseline testing strategy
No labs for classic uncomplicated dermatomal presentation
Clinical diagnosis typical
Avoid low value testing
Targeted labs for complications
Immunocompromised
Disseminated disease
Complication focused labs
Infection and inflammation markers
Complete blood count for systemic illness
Leukocytosis as bacterial superinfection clue
Neutropenia as immunosuppression clue
C reactive protein if severe systemic features
Supportive not diagnostic
Trend for bacterial superinfection
Organ function for antiviral safety
Creatinine and eGFR for antiviral dosing
Acyclovir crystalluria risk
Dose adjustment need
Liver enzymes if hepatitis concern
Alternative diagnosis screen
Medication baseline
CNS involvement labs
Cerebrospinal fluid adjuncts
CSF cell count and differential
Lymphocytic pleocytosis typical
Neutrophilic early possible
CSF protein and glucose
Elevated protein common
Glucose usually normal
Diagnostic Tests
Scoring Systems
Symptom and pain measurement tools
Zoster Brief Pain Inventory
Pain severity 0 to 10
Pain interference domains
DN4 neuropathic pain questionnaire
Neuropathic features screening
Guides neuropathic analgesia choice
Postherpetic neuralgia risk framing
Clinical risk factors
Older age
Severe acute pain
Severe rash burden
Counseling application
Early antiviral emphasis
Early pain control emphasis
MRI
Neuro complication imaging
MRI brain with and without contrast for encephalitis concern
Temporal lobe involvement possible
Differential includes HSV
MRI spine for myelitis concern
Cord signal changes
Evaluate compressive mimics
CT
Limited role imaging
CT head for acute neurologic deficit
Exclude hemorrhage or mass
Not sensitive for encephalitis
CT orbit and face if orbital cellulitis concern
Proptosis
Pain with eye movement
Ultrasound
Point of care applications
Soft tissue ultrasound if abscess concern
Fluctuance unclear
Guided drainage planning
Ocular ultrasound only if indicated and safe
Vision loss workup adjunct
Avoid pressure with globe injury concern
Virologic confirmation
Lesion testing
VZV PCR from lesion swab for atypical cases
Immunocompromised
Unclear diagnosis
Direct fluorescent antibody testing where available
Faster results
Lower sensitivity than PCR
CSF testing
CSF VZV PCR for meningitis or encephalitis concern
Higher specificity
Sensitivity variable
CSF VZV IgG intrathecal synthesis when PCR negative and suspicion high
Supports diagnosis
Specialist guided
Disposition
Discharge criteria
Outpatient pathway
Uncomplicated dermatomal disease
Stable vital signs
Tolerating oral intake
Safe outpatient antivirals and analgesia
Renal dosing arranged
Pain controlled with oral regimen
Follow up planning
Primary care within 48 to 72 hours if high pain burden
Analgesia adjustment
PHN prevention counseling
Ophthalmology same day for any ocular concern
V1 rash
Eye symptoms
Admission criteria
Inpatient indications
Disseminated zoster
Airborne plus contact precautions
IV antiviral therapy
Immunocompromised with extensive rash
Lower threshold for IV therapy
Monitor visceral involvement
CNS involvement
IV acyclovir
Neuro monitoring
Severe uncontrolled pain
Parenteral analgesia need
Neuropathic agent initiation monitoring
Transfer criteria
Higher level of care triggers
Vision threatening ocular disease
Corneal involvement
Uveitis concern
Suspected necrotizing infection or orbital cellulitis
Surgical service availability
Rapid progression
Treatment
Antiviral therapy
Oral antivirals for uncomplicated disease
Valacyclovir 1000 mg PO three times daily for 7 days
Preferred for dosing convenience
Renal dose adjustment required
Famciclovir 500 mg PO three times daily for 7 days
Alternative if valacyclovir unavailable
Renal dose adjustment required
Acyclovir 800 mg PO five times daily for 7 to 10 days
Lower bioavailability
Adherence barrier
IV antivirals for severe disease
Acyclovir 10 mg/kg IV every 8 hours
Use ideal body weight if obese
Dose adjust for renal function
Ensure IV hydration to reduce nephrotoxicity
Duration guidance
Continue until clinical improvement
Transition to oral to complete 10 to 14 days total for disseminated or CNS disease
Evidence tags for antiviral use
Class I recommendation for antivirals within 72 hours for immunocompetent adults
Supported by randomized trial evidence
Reduces acute pain duration
ACEP Level B style evidence tag for early antiviral therapy
Multiple RCTs and meta analyses support benefit
Greatest effect early
Pain control and neuropathic therapy
Baseline analgesics
Acetaminophen 1000 mg PO every 6 hours as needed
Maximum 3000 mg per day if older age or liver risk
Avoid duplicate products
Ibuprofen 400 mg PO every 6 to 8 hours as needed
Maximum 2400 mg per day typical
Avoid in CKD or GI bleed risk
Neuropathic agents
Gabapentin 300 mg PO at bedtime day 1
Titrate to 300 mg PO twice daily day 2
Titrate to 300 mg PO three times daily day 3
Further titration 300 mg per dose every 1 to 3 days as tolerated
Typical target 900 to 1800 mg per day
Renal dose adjustment required
Pregabalin 75 mg PO twice daily
Titrate to 150 mg PO twice daily within 1 week as needed
Renal dose adjustment required
Amitriptyline 10 to 25 mg PO nightly
Avoid in older adults when possible
Anticholinergic adverse effects
Opioid rescue for severe acute pain
Short course only
Avoid long duration use
Reassess within 48 to 72 hours
Oxycodone 5 mg PO every 6 hours as needed
Avoid with significant respiratory risk
Combine with bowel regimen if used
Topical therapy and skin care
Local measures
Cool wet compresses
Itch reduction
Lesion drying
Calamine lotion
Symptomatic itch relief
Avoid near eyes
Topical anesthetic for localized pain
Lidocaine 5% patch
Apply up to 12 hours on within 24 hours
Avoid on open vesicles
Steroids and adjuncts
Corticosteroids
Not routine for uncomplicated zoster
Limited evidence for long term PHN prevention
Risk in diabetes and immunosuppression
Consider only with specialist input for severe inflammatory complications
Ophthalmic uveitis
CNS vasculopathy
Antibiotics only if bacterial superinfection
Cephalexin 500 mg PO four times daily for 5 to 7 days
Cellulitis pattern
Purulence absent
Add MRSA coverage if risk factors
Prior MRSA
Purulent lesions
Specific syndromes
Herpes zoster ophthalmicus
Immediate systemic antiviral therapy
Start without delay for ophthalmology
Prefer valacyclovir or famciclovir
Topical ophthalmic therapy only under ophthalmology guidance
Avoid topical steroids without specialist
Avoid topical anesthetics outpatient
Ramsay Hunt syndrome
Systemic antiviral plus steroid early if specialist agrees
Higher risk of persistent facial weakness
ENT follow up
Special Populations
Pregnancy
Pregnancy considerations
Maternal zoster usually limited fetal risk
Reactivation differs from primary varicella
Maternal comfort and complication prevention focus
Antivirals in pregnancy
Acyclovir and valacyclovir generally considered acceptable when indicated
Shared decision making
Exposure counseling
Avoid contact with non immune pregnant individuals
Cover lesions until crusted
Geriatric
Older adult risks
Higher postherpetic neuralgia incidence
Early antiviral prioritization
Early neuropathic analgesia consideration
Medication safety
Avoid high anticholinergic burden
Renal dosing strict
Falls and delirium risk
Gabapentinoid start low and go slow
Avoid benzodiazepines for itch or sleep
Pediatrics
Pediatric presentation
Usually milder in immunocompetent children
Less PHN risk
Shorter course
Antiviral indications
Immunocompromised child
Ophthalmic involvement
Severe rash or pain
Weight based IV dosing
Acyclovir 10 to 15 mg/kg IV every 8 hours
Renal adjustment required
Background
Epidemiology
Disease burden
Reactivation of latent varicella zoster virus
Lifetime risk increases with age
Incidence rises after age 50
Postherpetic neuralgia frequency
Risk increases with age
Severe acute pain as predictor
Vaccination impact
Recombinant zoster vaccine reduces incidence
Breakthrough cases still occur
Pathophysiology
Viral mechanism
Latency in dorsal root ganglia or cranial nerve ganglia
Reactivation with immune decline
Anterograde spread along sensory nerve
Dermatomal inflammation and nerve injury
Neuropathic pain generation
Allodynia and hyperalgesia
Complication mechanisms
Ophthalmic involvement
Keratitis
Uveitis
CNS involvement
Meningitis
Encephalitis
Vasculopathy stroke risk
Therapeutic Considerations
Antiviral rationale
Inhibits viral replication
Reduced lesion formation
Reduced acute pain duration
Timing effect
Highest benefit early
Ongoing benefit in high risk beyond 72 hours
Pain strategy rationale
Mixed nociceptive and neuropathic pain components
NSAID and acetaminophen for nociceptive
Gabapentinoid or TCA for neuropathic
PHN prevention focus
Rapid control of acute neuritis
Early follow up for titration
Patient Discharge Instructions
copy discharge instructions
Discharge instructions
Diagnosis explanation
Shingles is reactivation of chickenpox virus in a nerve
Usually improves over 2 to 4 weeks
Medications
Antiviral exactly as prescribed
Pain regimen schedule
Skin care
Keep rash clean and dry
Do not scratch vesicles
Cover lesions until crusted
Contagion precautions
Avoid contact with people without chickenpox immunity
Avoid newborns
Avoid pregnant individuals without prior varicella or vaccination
Avoid immunocompromised contacts
Return to emergency care
Eye pain or vision change
Rash on forehead or tip of nose
Severe headache or stiff neck
Confusion or new weakness
Fever or rapidly spreading redness around rash
Widespread rash beyond one area
Pain not controlled with prescribed plan
Follow up
Primary care follow up within 2 to 3 days if pain significant
Ophthalmology same day for any eye symptoms
References
Guidelines and evidence sources
Core references
CDC shingles clinical overview and prevention guidance
Infection control and vaccination counseling
Recombinant zoster vaccine recommendations
ACIP recommendations for recombinant zoster vaccine
Adult vaccination indications
Immunocompromised considerations
IDSA guidance for management of VZV in immunocompromised hosts
IV acyclovir indications
Disseminated and CNS disease pathways
American Academy of Ophthalmology guidance on herpes zoster ophthalmicus
Urgent ophthalmology evaluation
Ocular complication prevention
Evidence tags for internal protocol use
Class I recommendation tag
Early systemic antiviral therapy for typical herpes zoster
IV acyclovir for disseminated or CNS disease
ACEP Level B style evidence tag
RCT supported oral antiviral benefit within 72 hours
Meta analysis supported acute pain reduction
ACEP Level C style evidence tag
Consultation triggers and disposition thresholds
Expert consensus and specialty society guidance
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.