Management of Chickenpox

Indications for Antiviral Treatment

• The American Academy of Pediatrics recommends antiviral therapy with aciclovir for patients who are at risk for complications, including those over 12 years of age 1
• The Centers for Disease Control and Prevention suggests that immunocompromised individuals should receive antiviral therapy with aciclovir 2, 1
• Patients with chronic cutaneous or pulmonary disorders should be considered for antiviral therapy with aciclovir 1
• The American College of Physicians recommends that patients receiving long-term salicylate therapy or corticosteroid therapy should receive antiviral therapy with aciclovir 1

Dosing Recommendations

• The recommended dose of oral aciclovir for children <45 kg is 20 mg/kg (maximum 400 mg/dose) 3-4 times daily for 5-10 days 1
• Adults and adolescents should receive 800 mg orally 4-5 times daily for 7-10 days 2, 1
• Intravenous aciclovir is recommended for severe disease or immunocompromised patients at a dose of 10 mg/kg IV every 8 hours 2, 1

Special Populations

• Immunocompromised patients require more aggressive treatment with intravenous aciclovir 2, 1
• The European Society for Clinical Microbiology and Infectious Diseases recommends that immunomodulator therapy should be discontinued in severe cases if possible 3, 4

Post-Exposure Prophylaxis

• The Centers for Disease Control and Prevention recommends that susceptible individuals exposed to chickenpox should receive varicella zoster immune globulin (VZIG) within 96 hours of exposure 5, 2
• If VZIG is unavailable, a 7-day course of aciclovir starting 7-10 days after exposure may be considered 2

Infection Control Measures

• The World Health Organization recommends that patients with active chickenpox should be isolated until all lesions have crusted over 6
• Healthcare workers with no evidence of immunity who are exposed to VZV should receive post-exposure vaccination and be furloughed from days 10-21 after exposure 6

Vaccination

• The American Academy of Pediatrics recommends vaccination for susceptible individuals but should not be administered to immunocompromised patients due to risk of disseminated viral infection 5
• Household contacts of susceptible immunocompromised individuals should be vaccinated if they are seronegative for HIV and have no history of chickenpox 5

Management of Chickenpox with Antiviral Therapy

Antiviral Treatment and Prophylaxis

• The Centers for Disease Control and Prevention recommends Varicella-Zoster Immune Globulin (VZIG) as the first-line prophylaxis for high-risk individuals, including immunocompromised patients, and must be administered within 96 hours of exposure, as it may prolong the incubation period to 28 days, requiring extended monitoring 7
• For alternative prophylaxis, the American Academy of Pediatrics suggests acyclovir 20 mg/kg (maximum 800 mg) four times daily for 5-7 days, initiated 7-10 days after exposure, for individuals who are unable to receive VZIG 8
• Post-exposure vaccination within 3-5 days may modify disease if infection has not yet occurred, according to the Centers for Disease Control and Prevention 9

Infection Control and Healthcare Personnel Management

• The Centers for Disease Control and Prevention recommends that unvaccinated healthcare personnel without immunity be furloughed from days 10-21 after exposure, and those with 1 dose of vaccine should receive a second dose within 3-5 days of exposure 9
• Healthcare personnel with 2 doses of vaccine should be monitored daily for fever and rash on days 8-21 post-exposure, as recommended by the Centers for Disease Control and Prevention 7

Management of Chickenpox in High-Risk Populations

Antiviral Treatment and Prophylaxis

• The Centers for Disease Control and Prevention recommends Varicella-Zoster Immune Globulin (VZIG) administration within 96 hours of exposure to high-risk susceptible individuals, including immunocompromised patients and pregnant women without immunity 10
• The American Academy of Pediatrics suggests that immunocompromised patients require aggressive treatment, and discontinue immunomodulator therapy if possible during active infection, with intravenous acyclovir initiated immediately at 10 mg/kg every 8 hours, as recommended by the CDC 10, 11
• The CDC recommends that patients on immunomodulators should not initiate therapy during active chickenpox, and consider temporary discontinuation in severe cases, with careful risk-benefit discussion 10, 12

Vaccination Considerations

• The American College of Rheumatology advises that varicella vaccine should not be administered to immunocompromised patients due to risk of disseminated viral infection, and VZV-naive patients on methotrexate should strongly consider vaccination before immunosuppression 13
• The CDC suggests that household contacts of immunocompromised individuals should be vaccinated if seronegative, and complete vaccination course at least 3 weeks before starting immunomodulators, as recommended by the Journal of Crohn's and Colitis 10, 13

Management of Varicella Infection in Immunocompromised Patients

Screening and Risk Assessment

• The European Crohn's and Colitis Organisation recommends screening all patients by history for prior chickenpox, shingles, or receipt of two doses of varicella vaccine to determine immunity status 14, 15
• Patients without a clear history of any of these should be tested for VZV IgG antibody to determine immunity status, as between 65-70% of adult patients are seropositive for VZV, meaning 30-35% remain susceptible 14, 15, 16, 17
• Seronegative (varicella-naive) patients face substantially higher risk of severe complications including pneumonia, hepatitis, encephalitis, and hemorrhagic disorders 14, 15

Vaccination Strategy for Varicella-Naive Patients

• The American Gastroenterological Association recommends completing the two-dose varicella vaccine series at least 3 weeks prior to starting any immunomodulator or immunosuppressive therapy 14, 15
• After vaccination, subsequent immunosuppressive therapy can only be commenced after waiting at least 3 weeks 14, 15
• If already on immunosuppression, vaccination requires a 3-6 month cessation of all immunosuppressive therapy before and after administration 14, 15

Critical Management Steps

• The European Crohn's and Colitis Organisation recommends discontinue immunomodulator therapy immediately during active chickenpox infection 14, 15
• Do not commence immunomodulator therapy during active infection 14, 15
• Immunomodulator therapy can only be reintroduced after all vesicles have crusted over and fever has resolved 14, 15
• In a review of VZV in IBD patients, five of 20 cases of varicella proved fatal, highlighting the severity in immunocompromised populations 14, 15

Common Pitfalls to Avoid

• The American Gastroenterological Association recommends never assuming immunity based on age alone—always verify history or serology 14, 15
• Never continue immunosuppressive therapy during active varicella infection in severe cases—this substantially increases mortality risk 14, 15