18 Nov 2025 Varicella School Outbreak Notice

The health department has recently identified a varicella (chickenpox) outbreak in a school and is sharing clinical reminders on the diagnosis and management of varicella. Varicella is a highly contagious disease that can be serious for non-immune pregnant people, newborns, and those with weak immune systems. If patients arrive at your office with rash, room them promptly to avoid waiting room exposures.

Varicella disease presents as low grade fever and a pruritic erythematous vesicular rash with up to 500 lesions in varying stages (see photo below). Immunized patients may develop milder and shorter disease course with modified rash showing less than 50 lesions and fewer to no vesicles.  

If you suspect varicella disease, send testing by unroofing a skin lesion and collecting lesion fluid/material with a synthetic swab and placing it in viral transport media (VTM) to send for polymerase chain reaction (PCR) test. These are typically the same swabs used for respiratory viral testing (i.e., COVID-19/flu/RSV). For further instructions on testing, refer to this specimen collection guidance. 

Patients with suspected or confirmed varicella should be asked to stay home from school, daycare, and other activities until the rash scabs and no new lesions appear for at least 24 hours. 

Immediately notify the Philadelphia Department of Health of any suspected cases by calling (215) 685-6741 during business hours (M-F, 8:30am-5:00pm). After hours, call (215) 685-6748 and leave a voicemail with information on the suspected case. Do not wait for test results to call. 

Continue to offer age-appropriate routine varicella vaccination to all eligible patients, and conduct recall of patients delayed on their immunizations for catch-up vaccination.

Varicella Vaccine Recommendations

As a reminder, 2 doses of varicella vaccine are recommended to protect against varicella.

Routine 2-dose vaccination

• First dose at 12 through 15 months old
• Second dose at 4 through 6 years old

Second dose catch-up vaccination

The minimum interval between doses is:

• 3 months for children younger than 13 years
• 4 weeks for people 13 years and older