Isolation Precautions for Herpes Zoster

For localized (dermatomal) herpes zoster in immunocompetent patients, implement standard precautions plus contact precautions until all lesions are crusted; for disseminated zoster (≥3 dermatomes) or any herpes zoster in immunocompromised patients, implement airborne precautions plus contact precautions in addition to standard precautions until all lesions are crusted. 1, 2

Standard precautions plus contact precautions are required for patients with localized dermatomal herpes zoster (confined to 1-2 dermatomes) who are immunocompetent 2
Cover all lesions with clothing or dressings to minimize transmission risk 1
Maintain these precautions until all lesions have completely crusted, as vesicular fluid contains infectious viral particles that can transmit varicella to susceptible individuals 1, 3, 2
Physical separation of at least 6 feet from other patients is recommended in healthcare settings 1

Airborne precautions plus contact precautions (in addition to standard precautions) are mandatory for disseminated zoster, defined as lesions in ≥3 dermatomes, visceral involvement, or hemorrhagic lesions 1
Place patient in negative-pressure isolation room 1
Healthcare workers must wear N95 respirators or equivalent when entering the room 1
Continue these precautions until all lesions are completely crusted 1

Airborne precautions plus contact precautions are required for all immunocompromised patients with herpes zoster, regardless of distribution, due to higher risk of dissemination 1, 4
Immunocompromised status includes active chemotherapy, HIV infection, chronic immunosuppressive agents (thiopurines, biologics, high-dose corticosteroids >40 mg prednisone daily), or organ transplantation 1
These patients develop new lesions for 7-14 days (versus 4-6 days in immunocompetent hosts) and heal more slowly, requiring prolonged isolation 1, 4

Healthcare workers with active herpes zoster must be excluded from duty until all lesions are completely dry and crusted 1
This applies regardless of whether the worker can cover the lesions, as viral shedding peaks in the first 24 hours when lesions are vesicular 5

Herpes zoster lesions are contagious to individuals who have not had chickenpox or varicella vaccination, potentially causing primary varicella infection in susceptible contacts 1, 3
Viral shedding is highest when lesions are vesicular; once all lesions have crusted, transmission risk is eliminated 5
Patients should avoid contact with pregnant women, immunocompromised individuals, and premature newborns until all lesions have crusted 1

Do not discontinue isolation at an arbitrary time point (e.g., 7 days); isolation must continue until the clinical endpoint of complete crusting is achieved 1
Do not use standard precautions alone for immunocompromised patients or disseminated disease—airborne precautions are mandatory 1
Do not assume localized zoster in an immunocompromised patient will remain localized—these patients require airborne precautions from the outset due to high dissemination risk 1, 4