What type of isolation is needed for a patient with herpes zoster?

Isolation Requirements for Herpes Zoster

For immunocompetent patients with localized herpes zoster, standard and contact precautions are sufficient with complete lesion coverage, maintaining at least 6 feet physical separation from other patients, and continuing precautions until all lesions are dried and crusted (typically 4-7 days after rash onset). 1

Isolation Type Based on Patient Status

Immunocompetent Patients with Localized Zoster

• Standard and contact precautions only - airborne precautions are NOT required 1
• Complete coverage of all lesions is mandatory 1
• Maintain minimum 6 feet physical separation from other patients 1, 2
• Patient should wear a surgical mask to prevent droplet transmission 1
• Continue precautions until all lesions are dried and crusted 1

Disseminated Herpes Zoster (Any Patient)

• Airborne AND contact precautions are mandatory, regardless of immune status 1
• Requires negative air-flow room 1
• Continue precautions until all lesions are dry and crusted 1
• Disseminated disease is defined as lesions in >3 dermatomes 3

Immunocompromised Patients with ANY Herpes Zoster

• Airborne AND contact precautions required until disseminated infection is ruled out 1
• Negative air-flow room is mandatory 1
• These patients experience prolonged viral shedding and slower healing (7-14 days or longer) 1
• Continue precautions until all lesions are completely dry and crusted 1

Duration of Isolation

The period of contagiousness begins 1-2 days before rash onset and continues until all lesions have dried and crusted, typically 4-7 days after rash onset. 1

• For lesions that do not crust (macules and papules), contagiousness ends when no new lesions appear within a 24-hour period 1
• Immunocompromised patients may require 7-14 days or longer due to slower healing 1
• Progressive varicella (new lesions for >7 days) indicates extended contagiousness beyond typical 4-7 days 1

Healthcare Worker Restrictions

• Healthcare workers with localized herpes zoster must cover all lesions completely and be restricted from caring for high-risk patients (immunocompromised, pregnant women, neonates, patients in protective environments) until all lesions have dried and crusted 1, 2
• Healthcare workers with disseminated zoster or immunocompromised workers with localized zoster must be excluded from duty until all lesions have dried and crusted 1
• Standard precautions with complete lesion coverage are mandatory even after return to work in high-risk settings 1

High-Risk Patient Avoidance

Patients with active herpes zoster should avoid contact with: 1, 2

• Pregnant women
• Premature infants and neonates
• Immunocompromised persons of all ages
• Anyone without history of chickenpox or varicella vaccination

Transmission Characteristics

• Herpes zoster is approximately 20% as transmissible as chickenpox 1
• Transmission occurs primarily through direct contact with fluid from active lesions 1
• Airborne transmission is possible but primarily documented in healthcare settings 4, 1
• Household transmission risk is approximately 20% of chickenpox risk 1
• Localized zoster is much less infectious than varicella or disseminated zoster 4

Common Pitfalls to Avoid

• Do not assume antiviral therapy immediately makes the patient non-contagious - viral shedding continues until lesions are fully crusted 1
• Do not allow healthcare workers with herpes zoster to care for high-risk patients before lesions are fully crusted 1
• Do not use inadequate lesion covering - this can lead to transmission even with localized disease 1
• Do not fail to recognize that immunocompromised patients may have prolonged viral shedding and require extended isolation 1
• Do not use only standard precautions for disseminated zoster or immunocompromised patients - airborne precautions with negative pressure rooms are required 1