Chickenpox (Varicella) - Prescribing & Patient Care Guide

Overview

Clinical Features to Confirm Diagnosis

Patient Categorization Before Prescribing

Antiviral Prescriptions

1. Oral Acyclovir (First-line for outpatient)

• Acyclovir 800 mg orally, 4 times daily for 5 days
• Must start within 24 hours of rash onset for maximum benefit

• Acyclovir 20 mg/kg per dose orally, 4 times daily for 5 days
• Maximum single dose: 800 mg

2. Valacyclovir (Better bioavailability, preferred in adults)

• Valacyclovir 1 g orally, 3 times daily for 5-7 days
• This is the preferred oral therapy over acyclovir due to simpler dosing and better absorption, per NIH OI guidelines

3. Famciclovir (Alternative oral agent)

• Famciclovir 500 mg orally, 3 times daily for 5-7 days

4. IV Acyclovir (Severe/complicated cases - hospital admission)

• Acyclovir 10 mg/kg IV every 8 hours for 7-10 days
• Switch to oral once fever resolves and clinical improvement confirmed (if no visceral involvement)

Symptomatic/Supportive Prescriptions

CRITICAL WARNING: NEVER use Aspirin (salicylates) in children or adolescents with varicella. It causes Reye syndrome (acute liver failure + encephalopathy). - Textbook of Family Medicine 9e

Nursing / Patient Care Instructions

Infection Control

• Isolate the patient until ALL lesions are crusted over (usually day 5-7 of rash)
• Airborne + contact precautions in hospital settings
• Susceptible household contacts should receive varicella vaccine within 3-5 days of exposure, or varicella-zoster immune globulin (VZIG) if immunocompromised

Skin Care

• Keep fingernails short and clean to prevent scratching and bacterial superinfection
• Apply calamine lotion to reduce itching
• Daily bathing with mild soap; pat dry gently - do not rub
• Avoid tight clothing; use loose, cool, cotton garments

Fever Management

• Tepid sponging for high fever
• Adequate hydration (fluids - water, ORS, fresh juices)
• Paracetamol only - avoid NSAIDs if possible (risk of necrotising fasciitis in some studies)

Oral Lesions

• Salt water gargles for oral ulcers
• Soft, cool foods; avoid acidic or spicy foods
• Topical anaesthetic mouth rinses if painful (lidocaine gel)

Rest & Activity

• Complete bed rest during the febrile phase
• Keep the patient in a cool, well-ventilated room
• Avoid school/work until all lesions are fully crusted

When to Escalate / Refer to Hospital

• High fever persisting beyond day 4-5, or fever returns after initial improvement
• Rapid breathing, chest pain, cough (suggests varicella pneumonia)
• Altered consciousness, severe headache, neck stiffness (suggests encephalitis/meningitis)
• Extensive rash in an immunocompromised person
• Lesions that are haemorrhagic or necrotic
• Neonatal varicella (mother had varicella within 7 days before/after delivery)
• Cerebellar ataxia (unsteady gait in a child)

Special Populations

Complications to Monitor For

• Cutaneous: Bacterial superinfection (most common in children), scarring
• Pulmonary: Varicella pneumonitis (most common serious complication in adults)
• Neurological: Cerebellar ataxia, encephalitis, transverse myelitis
• Hepatic: Hepatitis (usually subclinical)
• Rare: Reye syndrome (aspirin-associated), purpura fulminans

Quick Prescription Summary Card

Valacyclovir 1 g PO TDS x 5 days (start within 24 hrs of rash)
Paracetamol 500 mg PO QID PRN (fever/pain)
Cetirizine 10 mg PO OD (itching)
Calamine lotion - apply to lesions TDS
AVOID aspirin and ibuprofen

Acyclovir 20 mg/kg (max 800 mg) PO QID x 5 days
Paracetamol 10-15 mg/kg PO every 4-6 hrs PRN
Cetirizine 5 mg PO OD (2-6 yrs) or 10 mg OD (>6 yrs)
Calamine lotion topically
AVOID aspirin

Acyclovir 10 mg/kg IV every 8 hours x 7-10 days
Switch to oral once clinically improving

Varicella (Chickenpox) Vaccination - Complete Guide

Available Vaccines

Important: MMRV (ProQuad) is NOT approved for persons aged 13 years or older. Use single-antigen Varivax only in that group.

• Goldman-Cecil Medicine International Edition

Vaccine Efficacy

• 1 dose: Protects 70-90% against any disease, >95% against severe disease
• 2 doses: Approximately 90% effective against chickenpox overall; near-complete protection against severe disease
• Since the vaccination program began in the USA, there has been a >97% decrease in chickenpox cases
• Goldman-Cecil Medicine, p.179

Routine Immunization Schedule

Children (< 13 years)

Adolescents and Adults (≥ 13 years)

Who Should Be Vaccinated

• Children not previously vaccinated
• Unvaccinated adolescents and adults
• Healthcare workers without evidence of immunity
• Teachers, childcare workers
• College students, military recruits
• Non-pregnant women of childbearing age
• Travelers to high-risk areas
• Close contacts of immunocompromised persons

Evidence of Immunity (Vaccination NOT Needed If)

1. Documentation of 2 doses of varicella-containing vaccine (≥28 days apart)
2. Laboratory evidence of immunity (serology)
3. Laboratory confirmation of past varicella disease
4. Born in the USA before 1980 (except healthcare workers, pregnant persons, and immunocompromised - these still need proof)
5. Clinician-diagnosed or verified history of varicella or herpes zoster

Post-Exposure Vaccination

• Vaccinate within 3 days (72 hours) of exposure - reduces likelihood of symptomatic infection by approximately two-thirds
• If already had 1st dose, give the 2nd dose at the appropriate interval
• Use single-antigen varicella vaccine (no data for MMRV in post-exposure setting)

Contraindications (Who Should NOT Get the Vaccine)

Persons who receive the vaccine should not become pregnant for at least 1 month after vaccination.

Precautions

• Patients who are immunocompromised and cannot receive the live vaccine may receive Varicella-Zoster Immune Globulin (VZIG) after exposure as passive protection
• Vaccine must be stored at -50°C to -15°C - it is very temperature sensitive; do NOT use if cold chain was broken

What About Herpes Zoster (Shingles) - Related Vaccine

Side Effects of Varicella Vaccine

Transmission of vaccine virus to contacts is extremely rare and only occurs if the vaccinee develops a varicella-like rash.

Quick Reference Summary

CHILD (12 months - 12 years):
  Dose 1 at 12-15 months (Varivax OR ProQuad/MMRV)
  Dose 2 at 4-6 years (ProQuad preferred if giving MMR together)
  Min interval: 3 months

ADOLESCENT/ADULT (≥13 years):
  2 doses of Varivax only
  Min interval: 4 weeks (28 days)

POST-EXPOSURE (susceptible person):
  Vaccinate within 72 hours of exposure

SHINGLES PREVENTION (adults ≥50 yrs):
  Shingrix (RZV) - 2 doses, 2-6 months apart