When can a child with chickenpox return to school?

When to Return to School After Chickenpox

A child with chickenpox can return to school once all lesions have crusted over, which typically occurs 4-7 days after the rash first appears. 1

Standard Return-to-School Criteria

The key criterion for school return is complete crusting of all lesions, not a specific number of days. 1 This is because:

• The contagious period begins 1-2 days before rash onset and continues until all lesions are crusted 1
• Children remain infectious as long as any vesicular (fluid-filled) lesions are present 1
• Once all lesions have dried and crusted, the child is no longer contagious and can safely return to school 1

Typical Timeline

• Most immunocompetent children will have all lesions crusted within 4-7 days after rash onset 1
• The total isolation period from school is typically 5-7 days from when the rash first appears 2
• Some children may take slightly longer, particularly if they develop lesions in waves 3

Important Caveats

Do not rely on a fixed number of days—always verify that ALL lesions are completely crusted before returning to school. 1 Common pitfalls include:

• Sending children back too early when some lesions are still vesicular (fluid-filled), which maintains contagiousness 1
• Confusing "scabbed" with "crusted"—all lesions must be dry and crusted, not just scabbed over 1
• Missing lesions in the scalp, mouth, or genital areas that may crust later than visible skin lesions 1

Special Circumstances

Immunocompromised Children

• These children require extended isolation beyond the standard timeline 1
• They may develop new lesions for more than 7 days and remain contagious longer 1
• Return to school only after all lesions are crusted, which may take significantly longer than in healthy children 1

Breakthrough Varicella (Vaccinated Children)

• Children who develop chickenpox despite vaccination typically have milder disease with fewer lesions (often <50) 4
• They are still contagious and must follow the same return-to-school criteria 1
• The disease duration is typically shorter (4-6 days), so they may return sooner 1

During School Outbreaks

• Children who receive varicella vaccine as part of outbreak control measures may be readmitted to school immediately after vaccination 3
• Unvaccinated children without evidence of immunity who refuse vaccination should be excluded for 21 days after the last case's rash onset 3

Practical Verification Steps

Before allowing school return, verify:

• All visible lesions are completely dry and crusted (no fluid-filled vesicles remain) 1
• Check hidden areas: scalp, behind ears, between fingers and toes, genital area 1
• The child is afebrile and feels well enough to participate in normal activities 2