SIGNS AND SYMPTOMS 
- Varicella causes a spectrum of disease
- Classic childhood illness:
- Usually affects children ages 1–9
- Low-grade fever (100–103°F), headache, malaise, usually precedes rash by 1–2 days
- Pruritus, anorexia, and listlessness
- 10–21 day incubation period
- Infectious from 48 hr before vesicle formation until all vesicles are crusted, typically 3–7 days after onset of rash
- Classic exanthem:
- Lesions begin on the face, spreading to the trunk and extremities
- Papules, vesicles, or pustules, on erythematous base
- Lesions in varying stages of evolution, which is hallmark of Varicella
- "Dewdrop on rose petal"
- Vesicles 2–3 mm in diameter
- Duration of vesicle formation 3–5 days
- May involve conjunctival, oropharyngeal, or vaginal mucosa
- Skin superinfection with group A streptococcus or staphylococcus in 1–4% of healthy children
- Adolescents and adults:
- Similar presentation to children but greater risk of severe disease:
- Extracutaneous manifestations in 5–50%, particularly pneumonia
- Immunocompromised patients:
- HIV, transplant patients, leukemia patients at highest risk for disseminated form
- Patients on chemotherapy, immunosuppresants, and long-term corticosteroid therapy at high risk
- More numerous lesions that may have hemorrhagic base
- Healing may take longer
- Pneumonia common in these patients
- Pregnant patients:
- Prevalent in young expectant women
- More severe disease presentation:
- Risk to fetus greatest in 1st half of pregnancy
- Risk to mother greatest if infection in 2nd half of pregnancy
- Perinatal disease can occur from 5 days predelivery to 48 hr postdelivery
- Congenital varicella syndrome
- Occasionally follows maternal zoster infection
- Limb hypoplasia or paresis
- Microcephaly
- Ophthalmic lesions
- Extracutaneous manifestations:
- Pneumonitis:
- 25 times more common in adults
- Highest risk in adult smokers and immunocompromised children
- Occurs 3–5 days after onset of rash
- Signs: Continued eruption of new lesions, and new-onset cough
- Tachypnea, dyspnea, cyanosis, pleuritic chest pain, and hemoptysis
- Cerebellar ataxia:
- May develop 5 days after rash
- Ataxia, vomiting, slurred speech, fever, vertigo, tremor
- Cerebritis:
- Develops 3–8 days after start of rash
- Duration about 2 wk
- Progressive malaise
- Headache, meningismus, vomiting, fever, delirium, seizures
- Reye syndrome risk
Geriatric Considerations
- Increased risk of extracutaneous manifestations
- Lower immunity allows for reactivation as herpes zoster
Pediatric Considerations
- No aspirin for treatment of fever, possible association with Reye syndrome:
- Parents need to be cautioned regarding risk for secondary bacterial infection and possible progression to sepsis
Pregnancy Considerations
- Pregnant women with no childhood history of varicella and no antibodies to varicella zoster virus (VZV) require varicella zoster immunoglobulin (VZIG)
- Varicella pneumonia in pregnancy is medical emergency, associated with life-threatening respiratory compromise and death (mortality can be 10–45%)
- Likely to occur in 3rd trimester
History
- Thorough history:
- Fever, systemic symptoms
- Immunization history
- Immunocompetent vs. immunocompromised
Physical Exam
- Thorough physical exam:
- Characterize rash spread and extent
- Evaluate for any extracutaneous manifestations
ESSENTIAL WORKUP
- History and physical exam are sufficient in uncomplicated cases
- Pneumonitis:
- CXR shows 2–5 mm peripheral densities, may coalesce and persist for weeks
- Reye syndrome:
- Ammonia level peaks early
- LFTs will be elevated
- PT, PTT
- Cerebritis:
- Lumbar puncture demonstrates lymphocytic pleocytosis and elevated levels of protein
DIAGNOSIS TESTS & INTERPRETATION
Lab
- Viral culture (results in 3–5 days), polymerase chain reaction (PCR), or direct fluorescent antibody using skin scrapings from crust or base of lesion
- Serologic tests for varicella antibodies
- PCR is diagnostic method of choice, but uncomplicated patients need no labs
Imaging
Not generally indicated unless there is concern for extracutaneous manifestations
Diagnostic Procedures/Surgery
Liver biopsy definitive test for Reye syndrome
DIFFERENTIAL DIAGNOSIS
[Outline]
PRE-HOSPITAL
- Nonimmune transport personnel must avoid respiratory or physical contact with patients
- Transport personnel who have varicella or herpes zoster should not come in contact with immunocompromised or pregnant patients
INITIAL STABILIZATION/THERAPY
- Airway management and resuscitate as indicated:
- Protect airway if obtunded
ED TREATMENT/PROCEDURES
- Generally, acetaminophen and antipruritics are the keys to treating classic childhood illness
- Closely cropped nails and good hygiene help prevent secondary bacterial infection
- Infants/children ≤12 yr of age:
- Acyclovir:
- Recommended in children taking corticosteroids, long-term salicylate therapy, or chronic cutaneous or pulmonary diseases
- Modest benefit, reduces lesions by 25% and fever by 1 day
- Should be given within 24 hr of symptom onset
- NOT recommended in uncomplicated Varicella in healthy children
- Prophylaxis with VZIG in susceptible patients:
- Immunocompromised children at high risk for complication with significant exposure
- Susceptible children in the same household as person with active chickenpox or herpes zoster
- In 2012 FDA extended period for VZIG administration to 10 days after exposure
- VZIG in short supply, difficult to obtain
- Adolescents/adults:
- Acyclovir now recommended in adults with uncomplicated varicella initiated within 24 hr to decrease progression to disseminated disease
- Symptomatic treatment with antipyretics and antipruritics
- Pregnant women:
- If exposed to Varicella, no childhood history of varicella, no antibodies to VZV, need VZIG
- 80–90% immune from prior infection, need antibody testing prior to administration of VZIG
- Acyclovir or Valacyclovir prophylaxis especially during 2nd or 3rd trimesters:
- Safe during pregnancy (category B)
- IV acyclovir for pneumonitis/other complications:
- Respiratory, neurologic, hemorrhagic rash, or continued fever > 6 days
- Immunocompromised patients:
- IV Acyclovir recommended, poor PO bioavailability
- PO valacyclovir better bioavailability, approved in 2008 for lower risk immunocompromised patients
- Should be started within 24 hr of onset to maximize efficacy
- Foscarnet for acyclovir-resistant disease
- Prophylaxis with VZIG for the susceptible immunocompromised patient
- Extracutaneous:
- IV acyclovir or foscarnet if resistant
- Vaccine:
- Children:
- Routine vaccination for all susceptible children at 12 mo and older, 2 doses
- Adolescents and adults:
- Age 13 and older without history of varicella need vaccine
- 2 doses separated by 4–8 wk
- Recommended in high-risk groups: Health care workers, family member of immunocompromised person, susceptible women of childbearing age, teachers, military, international travelers
- Post exposure prophylaxis:
- Susceptible patients 12 mo or older, given with 72–120 hr, with 2nd dose at age appropriate interval
- Will produce immunity if not infected
- Immunocompromised persons:
- Most immunocompromised persons should not be immunized
MEDICATION
- Acyclovir:
- Uncomplicated: Adults: 800 mg PO QID for 5 days; Adolescents (13–18 yr old): 20 mg/kg per dose QID for 7 days; Peds: 20 mg/kg suspension PO QID for 5 days [max. 800 mg PO QID])
- Immunocompromised: Adults: 10 mg/kg IV q8h infused over 1 hr, or 800 mg PO 5 times a day for 7 days. Peds: 10–12 mg/kg IV q8h infused over 1 hr, or 500 mg/m2/day IV q8h for 7–10 days
- Valacyclovir: 1 g PO TID for 5–7 days
- Famciclovir: 500 mg PO TID for 7 days
- Foscarnet: Adults: 90 mg/kg q12h IV over 90–120 min for 2–3 wk; Peds: 40–60 mg/kg q8h over 120 min for 7–10 days; Foscarnet is not FDA approved
- Hydroxyzine: Adults: 25–50 mg IM or PO q4–6h. Peds: 0.5 mg/kg q4–6h suspension (supplied as 10 and 25 mg/5 mL)
- Diphenhydramine: Adults: 25–50 mg IV, IM, or PO q4h. Peds: 5 mg/kg/d elixir
- VZIG: Adults: 625 IU IM. Peds: 1 vial per 10 kg IM to a max. of 5 vials [each vial contains 125 IU])
[Outline]
DISPOSITION
Admission Criteria
- Patients with pneumonia require admission:
- ICU for respiratory observation or support
- Immunocompromised patients: ICU vs. ward, depending on severity of illness
- All admitted patients must be kept in isolation
Discharge Criteria
- Immunocompetent children without evidence of Reye syndrome or secondary bacterial infection
- Adults with no evidence of extracutaneous disease
FOLLOW-UP RECOMMENDATIONS
Patients who are discharged need close follow-up with PCP to assure resolution without complications
[Outline]
- Abramowicz M, Zuccotti G, Pflomm JM, eds. Drugs for non-HIV viral infections. Treatment Guidelines from The Medical Letter. New Rochelle: The Medical Letter, Inc. 2010;8:71–82.
- Albrecht MA. Treatment of varicella-zoster infection: Chickenpox. www.uptodate.com. Dec 12, 2012.
- American Academy of Pediatrics. Varicella-Zoster infections. In: Pickering L, ed. Red Book: 2012 Report of the Committee on Infectious Diseases, 29th ed. Elk Grove Village, IL: American Academy of Pediatrics, 2012:774–779.
- Flatt A, Breuer J. Varicella vaccines. Br Med Bull. 2012;103:115–127.
- Roderick M, Finn A, Ramanan AV. Chickenpox in the immunocompromised child. Arch Dis Child. 2012;97:587–589.
- van Lier A, van der Maas N, Rodenburg GD, et al. Hospitalization due to varicella in the Netherlands. BMC Infect Dis. 2011;11:85.
See Also (Topic, Algorithm, Electronic Media Element)
Herpes Zoster