What is the recommended isolation period for herpes zoster?

Isolation Duration for Herpes Zoster

For localized herpes zoster in immunocompetent healthcare personnel, cover the lesions and restrict from care of high-risk patients until all lesions dry and crust; for disseminated or localized disease in immunocompromised persons, exclude from duty until all lesions dry and crust. 1

Isolation Recommendations by Clinical Scenario

Immunocompetent Patients with Localized Herpes Zoster

• Cover lesions and restrict from care of high-risk patients (e.g., neonates, pregnant women, immunocompromised individuals) until all lesions dry and crust 1
• Healthcare personnel may continue working in other settings with appropriate lesion coverage 1
• Athletes with herpes zoster should be excluded from competition until all lesions are fully crusted or until a physician provides written documentation that the condition is noninfectious 1

Immunocompromised Patients or Disseminated Disease

• Complete exclusion from duty until all lesions dry and crust 1
• This applies to both disseminated zoster and localized zoster in immunocompromised persons until disseminated infection is ruled out 1
• Immunocompromised patients may develop lesions over 7-14 days (versus 4-6 days in healthy hosts) and heal more slowly without antiviral therapy 1

Timeline Considerations

Typical Disease Course

• In immunocompetent hosts, lesions continue to erupt for 4-6 days, with total disease duration of approximately 2 weeks 1
• Lesions progress from macules to papules to vesicles to pustules before crusting over in 7-10 days 2
• Infected persons remain contagious until all lesions are crusted, typically 4-7 days after rash onset for varicella, but potentially longer for herpes zoster 1

Extended Course in Immunocompromised Hosts

• Lesions may continue developing over 7-14 days and heal more slowly without effective antiviral therapy 1
• Some patients develop chronic ulcerations with persistent viral replication complicated by secondary infections 1

Transmission Risk and Precautions

Contagiousness

• Herpes zoster is transmitted through direct contact with vesicular fluid or inhalation of aerosolized particles from skin lesions 1
• The virus can cause varicella in susceptible individuals who have not had chickenpox or vaccination 1
• Breakthrough varicella (in vaccinated persons) is also contagious despite typically being milder 1

Post-Exposure Management for Healthcare Personnel

• Healthcare personnel without evidence of varicella immunity exposed to disseminated zoster or localized zoster with uncontained/uncovered lesions should be excluded from duty from day 8 after first exposure through day 21 (or day 28 if varicella-zoster immune globulin was administered) after last exposure 1
• If varicella develops, exclude until all lesions dry and crust 1

Critical Pitfalls to Avoid

• Do not allow return to work or competition based solely on time elapsed—the endpoint is complete crusting of all lesions, not a specific number of days 1
• Do not assume immunocompromised patients follow the same timeline as immunocompetent hosts—they require longer isolation and closer monitoring 1
• Do not overlook the risk to susceptible contacts—herpes zoster can transmit varicella-zoster virus to individuals without immunity 1
• Ensure lesions are truly crusted, not just covered—covering alone is insufficient for return to care of high-risk patients in healthcare settings 1