Isolation Duration for Varicella (Chickenpox)
Patients with varicella should remain in isolation until all lesions are crusted, which typically occurs 4-7 days after rash onset in immunocompetent individuals. 1
Immunocompetent Patients
Standard isolation duration is from 1-2 days before rash onset until all lesions have crusted over, typically 4-7 days after rash appears. 1
The period of contagiousness begins 1-2 days before the onset of rash and ends when all lesions are crusted. 1
Fever and rash typically last approximately 5 days in healthy individuals with wild-type disease. 1
Patients should be isolated using airborne precautions (negative air-flow rooms) and contact precautions throughout this entire period. 1
If negative air-flow rooms are unavailable, patients should be isolated in closed rooms and avoid contact with persons without evidence of immunity to varicella. 1
Immunocompromised Patients
Immunocompromised patients require extended isolation because they may develop progressive varicella with new lesions continuing for >7 days and remain contagious longer. 1
Airborne and contact precautions should be maintained until all lesions are dry and crusted, which may take significantly longer than in immunocompetent hosts. 1
These patients often develop more severe disease lasting up to two weeks, with more numerous skin lesions, often with hemorrhagic base, and high possibility for cutaneous dissemination. 2
For immunocompromised patients with disseminated herpes zoster, isolation precautions should continue until disseminated infection is ruled out and all lesions are crusted. 1
Special Considerations
Persons who develop progressive varicella (development of new lesions for >7 days) are contagious longer due to depressed immune response allowing persistent viral replication. 1
Healthcare personnel caring for varicella patients should have documented evidence of immunity to varicella. 1
Only healthcare personnel with evidence of immunity should provide care for patients with confirmed or suspected varicella. 1
Breakthrough varicella in vaccinated persons is contagious despite typically being milder with <50 skin lesions and shorter duration (4-6 days). 1