Acute varicella-zoster (chickenpox) normally presents in childhood and is usually self-limiting.
Adults, pregnant women, immunosuppressed patients, and neonates are at high risk of complications from varicella, including pneumonia, neurological sequelae, hepatitis, secondary bacterial infection, and death.
Patients in high-risk categories should receive treatment with antiviral therapy.
While most countries in Europe do not currently vaccinate children against varicella, vaccination strategies differ widely within the EU, with a few countries incorporating the vaccine into routine childhood vaccination, and others recommending it to susceptible adolescents and adults. In the US, varicella vaccine is currently recommended for immunocompetent children and susceptible adults (e.g., healthcare workers, those occupationally exposed to children, people admitted to hospital, military recruits).
Patients with high risk for severe disease who have had significant exposure to the virus and in whom the vaccine is contraindicated (i.e., neonates, pregnant women, immunocompromised people, and those receiving high-dose systemic immunosuppressive therapy) may receive immunoprophylaxis or post-exposure antiviral prophylaxis.
Varicella (chickenpox), one of the childhood exanthems, is caused by the human alpha herpes virus, varicella zoster. Varicella-zoster virus (VZV) is an exclusively human virus. The incubation period is about 14 days (range 9 to 21 days). Varicella is characterised by fever, malaise, and a generalised pruritic, vesicular rash. The disease normally presents in childhood and is usually self-limiting. Adverse outcomes are more common in immunocompromised people, adolescents, adults, and pregnant women.
History and exam
Key diagnostic factors
- presence of risk factors
- vesicular rash
- vesicles on mucous membranes
Other diagnostic factors
- sore throat
- exposure to varicella
- age 1 to 9 years
- unimmunised status
- occupational exposure
1st investigations to order
- clinical diagnosis
Investigations to consider
- polymerase chain reaction
- viral culture
- direct fluorescent antibody testing (DFA)
- Tzanck smear
- latex agglutination (LA)
- enzyme-linked immunosorbent assay (ELISA)
- complement fixation
- ultrasound (pregnant women)
otherwise healthy children at low risk of severe disease
increased risk of moderate to severe disease
high risk of severe disease
Andrew Riordan, MD, FRCPCH, MRCP, DTM&H
Consultant in Paediatric Infectious Diseases and Immunology
Royal Liverpool Children's Hospital (Alder Hey)
AR declares that he has no competing interests.
Dr Andrew Riordan would like to gratefully acknowledge Dr Steven Pergam, Dr Rupali Jain, and Dr Anna Wald, previous contributors to this topic.
SP has served as a consultant for Merck & Co., Inc, Optimer/Cubist, and Chimerix, and has participated in clinical trials with these three organizations. He is also an author of a paper cited in this topic. RJ declares that she has no competing interests. AW is a member of the Data and Safety Monitoring Board (DSMB) for a Merck study of a candidate VZV vaccine.
Chad M. Hivnor, Major, USAF, MC, FS
Outpatient & Pediatric Dermatology
59th Medical Wing/ SGOMD
Lackland Air Force Base
CMH declares that he has no competing interests.
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