Doctor123.org

Varicella, Emergency Medicine

Basics

Description

- DNA virus: - Latency in cranial nerve ganglia, dorsal root ganglia, and autonomic ganglia with periodic reactivation - Presents as herpes zoster or shingles decades after primary infection - Virus is transmitted by respiratory route and direct contact with skin lesions - Humans are only known reservoir

- 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

- 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

- 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

- Thorough physical exam: - Characterize rash spread and extent - Evaluate for any extracutaneous manifestations

- 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

  • Commonly known as chickenpox
  • Most common in late winter and early spring
  • Vaccine has reduced incidence by 85%
  • Adults have a 15 times greater risk for death from varicella than children

Etiology

  • DNA virus:Latency in cranial nerve ganglia, dorsal root ganglia, and autonomic ganglia with periodic reactivationPresents as herpes zoster or shingles decades after primary infectionVirus is transmitted by respiratory route and direct contact with skin lesionsHumans are only known reservoir

Diagnosis

Signs and Symptoms

  • Varicella causes a spectrum of disease
  • Classic childhood illness:Usually affects children ages 1 " 9Low-grade fever (100 " 103 °F), headache, malaise, usually precedes rash by 1 " 2 daysPruritus, anorexia, and listlessness10 " 21 day incubation periodInfectious from 48 hr before vesicle formation until all vesicles are crusted, typically 3 " 7 days after onset of rashClassic exanthem:Lesions begin on the face, spreading to the trunk and extremitiesPapules, vesicles, or pustules, on erythematous baseLesions in varying stages of evolution, which is hallmark of Varicella "Dewdrop on rose petal "Vesicles 2 " 3 mm in diameterDuration of vesicle formation 3 " 5 daysMay involve conjunctival, oropharyngeal, or vaginal mucosaSkin 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 formPatients on chemotherapy, immunosuppresants, and long-term corticosteroid therapy at high riskMore numerous lesions that may have hemorrhagic baseHealing may take longerPneumonia common in these patients
  • Pregnant patients:Prevalent in young expectant womenMore severe disease presentation:Risk to fetus greatest in 1st half of pregnancyRisk to mother greatest if infection in 2nd half of pregnancyPerinatal 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 adultsHighest risk in adult smokers and immunocompromised childrenOccurs 3 " 5 days after onset of rashSigns: Continued eruption of new lesions, and new-onset coughTachypnea, dyspnea, cyanosis, pleuritic chest pain, and hemoptysisCerebellar ataxia:May develop 5 days after rashAtaxia, vomiting, slurred speech, fever, vertigo, tremorCerebritis:Develops 3 " 8 days after start of rashDuration about 2 wkProgressive malaiseHeadache, meningismus, vomiting, fever, delirium, seizuresReye syndrome risk
  • Increased risk of extracutaneous manifestations
  • Lower immunity allows for reactivation as herpes zoster
  • No aspirin for treatment of fever, possible association with Reye syndrome:Acetaminophen " is recommended antipyretic treatment
  • Parents need to be cautioned regarding risk for secondary bacterial infection and possible progression to sepsis
  • 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 symptomsImmunization historyImmunocompetent vs. immunocompromised

Physical Exam

  • Thorough physical exam:Characterize rash spread and extentEvaluate 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 earlyLFTs will be elevatedPT, 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

  • Impetigo
  • Disseminated herpes
  • Disseminated coxsackievirus
  • Measles
  • Rickettsial disease
  • Insect bites
  • Scabies
  • Erythema multiforme
  • Drug eruption (especially Stevens " Johnson syndrome)

Treatment

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 diseasesModest benefit, reduces lesions by 25% and fever by 1 dayShould be given within 24 hr of symptom onsetNOT recommended in uncomplicated Varicella in healthy childrenProphylaxis with VZIG in susceptible patients:Immunocompromised children at high risk for complication with significant exposureSusceptible children in the same household as person with active chickenpox or herpes zosterIn 2012 FDA extended period for VZIG administration to 10 days after exposureVZIG 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 diseaseSymptomatic treatment with antipyretics and antipruritics
  • Pregnant women:If exposed to Varicella, no childhood history of varicella, no antibodies to VZV, need VZIG80 " 90% immune from prior infection, need antibody testing prior to administration of VZIGAcyclovir 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 bioavailabilityPO valacyclovir better bioavailability, approved in 2008 for lower risk immunocompromised patientsShould be started within 24 hr of onset to maximize efficacyFoscarnet for acyclovir-resistant diseaseProphylaxis 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 dosesAdolescents and adults:Age 13 and older without history of varicella need vaccine2 doses separated by 4 " 8 wkRecommended in high-risk groups: Health care workers, family member of immunocompromised person, susceptible women of childbearing age, teachers, military, international travelersPost exposure prophylaxis:Susceptible patients 12 mo or older, given with 72 " 120 hr, with 2nd dose at age appropriate intervalWill produce immunity if not infectedImmunocompromised 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])

Follow-Up

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

Followup Recommendations

Patients who are discharged need close follow-up with PCP to assure resolution without complications

Pearls and Pitfalls

  • Patients with varicella are infectious from 48 hr before vesicle formation until all vesicles are crusted
  • Immunocompromised patients with Varicella need careful consideration and admission in most cases
  • Varicella pneumonia is medical emergency, particularly in pregnancy

Additional Reading

  • 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

Codes

ICD9

  • 052.9 Varicella without mention of complication
  • 053.9 Herpes zoster without mention of complication
  • 053.21 Herpes zoster keratoconjunctivitis
  • 052.1 Varicella (hemorrhagic) pneumonitis
  • 052.7 Chickenpox with other specified complications
  • 052.8 Chickenpox with unspecified complication

ICD10

  • B01.9 Varicella without complication
  • B02.9 Zoster without complications
  • B02.31 Zoster conjunctivitis
  • B01.2 Varicella pneumonia
  • B01.89 Other varicella complications

SNOMED

  • 38907003 varicella (disorder)
  • 4740000 Herpes zoster (disorder)
  • 410509003 Herpes zoster conjunctivitis
  • 195911009 chickenpox pneumonia (disorder)
  • 423333008 Exanthem due to chicken pox (disorder)
  • 90433002 Congenital varicella infection