Chickenpox (varicella) in nonpregnant adults who are immunocompetent

Chickenpox (varicella) is caused by a primary infection with varicella zoster virus (VZV). Management of chickenpox depends on the patient’s age, comorbidities, and clinical presentation.

Consider antiviral therapy for immunocompetent nonpregnant adults with chickenpox, regardless of varicella immunisation status. Antiviral therapy can reduce the severity of symptoms and may decrease the risk of complications (eg pneumonitis, encephalitis, hepatitis). If possible, start antiviral therapy within 24 hours of rash onset for maximum benefitBalfour, 2001Center for Disease Control (CDC), 2022Wallace, 1992; use:

1valaciclovir 1 g orally, 8-hourly for 7 days. For dosage adjustment in adults with kidney impairment, see valaciclovir dosage adjustment valaciclovir valaciclovir valaciclovir

OR

1famciclovir 500 mg orally, 8-hourly for 7 days. For dosage adjustment in adults with kidney impairment, see famciclovir dosage adjustment famciclovir famciclovir famciclovir

OR

2aciclovir 800 mg orally, 5 times daily for 7 days. For dosage adjustment in adults with kidney impairment, see aciclovir oral dosage adjustment. aciclovir aciclovir aciclovir

For management of immunocompetent adults with complications of chickenpox and adults with immune compromise who develop chickenpox see here.

Supportive care for patients with chickenpox includes:

  • keeping fingernails short to avoid excoriation and secondary bacterial infection
  • managing pruritus with an oral antihistamine
  • relieving discomfort with paracetamol; managing fever with paracetamol is not routinely required.

Secondary bacterial infection of chickenpox skin lesions with Streptococcus pyogenes (group A streptococcus [GAS]) or Staphylococcus aureus can occur and should be treated as for cellulitis. If other organisms are identified on culture, alternative antimicrobials may be required.

For management of patients exposed to varicella zoster virus, including the use of varicella vaccine or high-titre zoster immunoglobulin (ZIG), see the Australian Immunisation Handbook.