Varicella: Difference between revisions

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==Background==
==Background==
*Also known as "Chicken Pox"
*Caused by [[varicella zoster virus]] causing varicella (chicken pox) and later zoster ([[Shingles]])
*Contagious until last lesion crusts over
*Contagious until last lesion crusts over


==Diagnosis==
==Clinical Features==
*Pruritic generalized vesicular exanthem w/ mild systemic manifestations
[[File:Vicki Pandit - Howrah 2014-04-06 9845.jpg|thumb|Chickenpox rash on face.]]
[[File:Varicela Rash.jpg|thumbnail|Male with varicella rash: lesions in various stages of development]]
[[File:Chickenpox blister.jpg|thumbnail|Classic blister during early stage of lesion development]]
*[[pruritus|Pruritic]] generalized vesicular exanthem with mild systemic manifestations
*Usually affects children <10y
*Usually affects children <10y
*Rash
 
**Starts on trunk or scalp as pruritic, red macules, spreads to extremities
===[[Rash]]===
**W/in 24hr rash becomes vesicular (on erythematous base)
*Starts on trunk or scalp as pruritic, red macules, spreads to extremities
**Palms/soles spared
*Within 24hr rash becomes vesicular (on erythematous base)
**Lesions in various stages of development
*Palms/soles spared
*Lesions in various stages of development
 
===Complications===
*Can include [[encephalitis]], [[otitis media]], [[pneumonia]], [[hepatitis]], [[strep]]/[[staph]] [[cellulitis|superinfection]] of ruptured vesicles
*Perinatal infection in neonates may develop serious illness


==Differential Diagnosis==
==Differential Diagnosis==
*[[Smallpox]]
{{Peds Rash DDX}}
{{Bullous rashes DDX}}
{{VZV types}}
 
==Evaluation==
*Typically made on clinical features


==Treatment==
==Management==
*Tylenol, antihistamine, oatmeal baths
===Supportive Care===
*No Aspirin (may predispose to Reye syndrome)
*[[Tylenol]], [[antihistamine]], oatmeal baths
*Routine use of antiretrovirals for uncomplicated cases in immunocompetent children is not recommended (Tintinallli 7th ed)
*Avoid aspirin in young children due to the risk of [[Reye syndrome]]
*Immunocompromised: IV acyclovir or high-dose PO tx (600mg/m2/day)
 
===Antivirals===
*Routine use of antiretrovirals for uncomplicated cases in immunocompetent children is not recommended <ref>Arvin AM: Antiviral therapy for varicella and herpes zoster. Semin Pediatr Infect Dis 2002; 13:12.</ref>
*However, evidence shows decreased days of fever and number of lesions<ref>Klassen TP, et al. Acyclovir for treating varicella in otherwise healthy children and adolescents. Cochrane Database Syst Rev. 2005; (4):CD002980.</ref>
AAP recommends antiviral treatment (within 24hrs) for patients at risk of increased illness severity:
*Any patient older than 12 years of age
*Patients with chronic cutaneous or pulmonary disorders
*Patients receiving long-term salicylate therapy
*Patients receiving short, intermittent, or aerosolized courses of corticosteroids
 
Other cases to consider [[acyclovir]]
*Also consider in <ref>Drugs for non-HIV viral infections. Treat Guidel Med Lett. 2007; 5(59):59-70.</ref>:
*Pregnancy<ref name="cdc">CDC Chicken pox acyclovir treatment [http://www.cdc.gov/chickenpox/hcp/persons-risk.html#acyclovir]</ref>
====Immunocompetent Adult====
*[[Acyclovir]] 800mg PO q6hrs daily x 5 days '''OR'''
*[[Valacyclovir]] 1000mg PO q8hrs daily x 14 days '''OR'''
*[[Famiciclovir]] 500mg PO q8hrs x 14 days
====Immunocompromised Adult====
*[[Acyclovir]] 10mg/kg IV q8hrs x 7 days
====At risk children <12yo child based on AAP criteria====
*[[Acyclovir]] 20mg/kg PO q6hrs daily x 5 days
*[[Acyclovir]] 10mg/kg IV q8hrs daily x 7 days
 
====VZIG====
*Initiate VZIG alongside acyclovir for inpatient treatment of child or adult
*For immunocompromised child with exposure, give as post-exposure prophylaxis if<ref>CDC. MMWR - updated recommendations for use of VariZIG - United States, 2013. July 19, 2013 / 62(28);574-576.</ref>:
**Within 10 days window of exposure
**VZIG given IM as 125 IU/10 kg of body weight
***Up to max of 625 IU
***Minimum dose 62.5 IU for patients weighing ≤ 2.0 kg
***Minimum dose 125 IU for weight 2.1 - 10.0 kg
*VZIG may prolong incubation period ≥1 week
**Must have patient closely follow up for signs and symptoms for 28 days after exposure
**If signs or symptoms of varicella occur, antiviral therapy must be started immediately
 
==Disposition==
 
==Vaccine==
*Introduced in 2006. Prior to introduction, incidence prior to adolescence approached 90% in US
*Vaccine is 85% effective against all disease, 90% effective against severe disease (greater than 1000 lesions)
*Typically given at age 5 in USA
*Post-exposure prophylaxis:
**Ideally given within 3-5 days of exposure in immunocompetent patients
**If immunocompromised patient is being given VZIG, varicella vaccine should be administered ≥5 months after VariZIG administration<ref>CDC. Prevention of varicella: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 2007;56(No. RR-4).</ref>


==Complications==
*Can include encephalitis, pneumonia, hepatitis, strep/staph superinfection of ruptured vesicles
*Perinatal infection in neonates may develop serious illness
==See Also==
==See Also==
[[Pediatric Rashes]]
[[Pediatric Rashes]]


[[Category:Derm]]
==References==
<references/>
 
[[Category:Dermatology]]
[[Category:ID]]
[[Category:ID]]
[[Category:Peds]]
[[Category:Pediatrics]]

Revision as of 21:03, 8 September 2020

Background

Clinical Features

Chickenpox rash on face.
Male with varicella rash: lesions in various stages of development
Classic blister during early stage of lesion development
  • Pruritic generalized vesicular exanthem with mild systemic manifestations
  • Usually affects children <10y

Rash

  • Starts on trunk or scalp as pruritic, red macules, spreads to extremities
  • Within 24hr rash becomes vesicular (on erythematous base)
  • Palms/soles spared
  • Lesions in various stages of development

Complications

Differential Diagnosis

Pediatric Rash

Vesiculobullous rashes

Febrile

Afebrile

Varicella zoster virus

Evaluation

  • Typically made on clinical features

Management

Supportive Care

Antivirals

  • Routine use of antiretrovirals for uncomplicated cases in immunocompetent children is not recommended [1]
  • However, evidence shows decreased days of fever and number of lesions[2]

AAP recommends antiviral treatment (within 24hrs) for patients at risk of increased illness severity:

  • Any patient older than 12 years of age
  • Patients with chronic cutaneous or pulmonary disorders
  • Patients receiving long-term salicylate therapy
  • Patients receiving short, intermittent, or aerosolized courses of corticosteroids

Other cases to consider acyclovir

  • Also consider in [3]:
  • Pregnancy[4]

Immunocompetent Adult

Immunocompromised Adult

At risk children <12yo child based on AAP criteria

VZIG

  • Initiate VZIG alongside acyclovir for inpatient treatment of child or adult
  • For immunocompromised child with exposure, give as post-exposure prophylaxis if[5]:
    • Within 10 days window of exposure
    • VZIG given IM as 125 IU/10 kg of body weight
      • Up to max of 625 IU
      • Minimum dose 62.5 IU for patients weighing ≤ 2.0 kg
      • Minimum dose 125 IU for weight 2.1 - 10.0 kg
  • VZIG may prolong incubation period ≥1 week
    • Must have patient closely follow up for signs and symptoms for 28 days after exposure
    • If signs or symptoms of varicella occur, antiviral therapy must be started immediately

Disposition

Vaccine

  • Introduced in 2006. Prior to introduction, incidence prior to adolescence approached 90% in US
  • Vaccine is 85% effective against all disease, 90% effective against severe disease (greater than 1000 lesions)
  • Typically given at age 5 in USA
  • Post-exposure prophylaxis:
    • Ideally given within 3-5 days of exposure in immunocompetent patients
    • If immunocompromised patient is being given VZIG, varicella vaccine should be administered ≥5 months after VariZIG administration[6]

See Also

Pediatric Rashes

References

  1. Arvin AM: Antiviral therapy for varicella and herpes zoster. Semin Pediatr Infect Dis 2002; 13:12.
  2. Klassen TP, et al. Acyclovir for treating varicella in otherwise healthy children and adolescents. Cochrane Database Syst Rev. 2005; (4):CD002980.
  3. Drugs for non-HIV viral infections. Treat Guidel Med Lett. 2007; 5(59):59-70.
  4. CDC Chicken pox acyclovir treatment [1]
  5. CDC. MMWR - updated recommendations for use of VariZIG - United States, 2013. July 19, 2013 / 62(28);574-576.
  6. CDC. Prevention of varicella: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 2007;56(No. RR-4).