Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Chicken pox @ daa july 15

874 views

Published on

Varicella Infections in children ( Ref Nelson 19th Edition)

Published in: Health & Medicine
  • Be the first to comment

Chicken pox @ daa july 15

  1. 1. Dr. Avdhesh Agrawal Registrar – Dr Atul’s Child Hospital Varicella-Zoster Virus Infections
  2. 2.  Bushra SDPICU/ DR-6  Yrs Female Child  Fever  Rash  Malaise  Anorexia  Headache  Rash- Intense Pruritic  Difficulty in Standing  Abnormal Gait  Sick Look
  3. 3. Noted Points  History of Contact  Distribution of Rashes  Crops of Rashes in various phases  Systemic Symptoms subsided in 3-4 days
  4. 4. About the culprit Agent  Virus  NEUROTROPIC  human herpesvirus- Alpha Herpes Virus  virus is enveloped with double-stranded DNA genomes  encode more than 70 proteins
  5. 5. What does it do....?  Varicella-zoster virus (VZV) causes primary, latent, and recurrent infections.  The primary infection is manifested as varicella (chickenpox)  Recurrent infection known as Herpes zoster / Shingles
  6. 6. Interesting Data  USA –  Annual Case – 40 Lakh ,  Hospitalizations – 11000-15000  Deaths- 100-150  Primary Varicella – Mortality Rate- 2-3/ 100000 cases  Lowest among 1-9 yrs of age  Infants – 4 times risk  Adults – 25 times risk of dying  Mortality rate is 7-14% in untreated primary infection in immunocompromised children  50 % in untreated adults with pneumonia  transmission of VZV to susceptible individuals occurs at a rate of 65-86%  contagious 24-48 hr before the rash is evident and until vesicles are crusted  2 Days before to 7 days/ crusting
  7. 7. Contagiousness 1-2 days all lesions are crusted 5 days
  8. 8. Pathogenesis  VZV is transmitted in  by airborne spread - oropharyngeal secretion  through direct contact - fluid of skin lesions
  9. 9. Pathogenesis......Contd
  10. 10.  Virus is transported in a retrograde manner through sensory axons dorsal root ganglia throughout the spinal cord virus establishes latent infection in the neurons and satellite cells Subsequent reactivation of latent virus herpes zoster
  11. 11. Clinical Manifestation  Varicella (Chicken pox)  Varicella Zoster/ Herpes Zoster  Breakthrough varicella  Progressive varicella  Neonatal varicella  Congenital varicella syndrome
  12. 12. Varicella (Chickenpox)  Acute Febrile Rash  incubation period is 10 -21 days.  Subclinical varicella is rare  Prodromal symptoms  Fever  malaise  anorexia  headache  mild abdominal pain  Systemic Symptoms resolves within 2-4 days after onset of rash
  13. 13.  Varicella lesions  appear first on the scalp, face, or trunk.  Centripetal Distribution  The initial exanthem consists of intensely pruritic  erythematous macules  papular stage  fluid-filled vesicles.  Clouding and umbilication of the lesions begin in 24-48 hr.
  14. 14. • simultaneous presence of lesions in various stages of evolution is characteristic of varicella • The number of varicella lesions 10 to 1,500 • Ulcerative lesions involving the mucosa of oropharynx and vagina
  15. 15.  vesicular lesions on the eyelids and conjunctivae and mucosa  The exanthem may be much more extensive in children with skin disorders  Hypopigmentation or hyperpigmentation of lesion sites persists for days to weeks.  No Scarring or marks
  16. 16. differential diagnosis  vesicular rashes caused by other infectious agents :-  enterovirus  monkey pox  rickettsial pox  S. aureus  drug reactions  disseminated herpes zoster  contact dermatitis  insect bites  Small Pox
  17. 17. Herpes zoster  reactivation of latent VZV.  uncommon in childhood  Zoster is not caused by exposure to a patient with varicella  The lifetime risk for herpes zoster for individuals with a history of varicella is 10-20%  75% of cases occurring after 45 yr of age.  Herpes zoster is very rare in healthy children <10 yr of age  2nd episode of HZ 4%  3 or more episodes are rare  Is Herpes Zoster Infectious ......???
  18. 18. vesicular rash that usually is dermatomal in distribution. necrotic changes may be produced in the associated ganglia. The skin lesions of varicella and herpes zoster have identical histopathology infectious VZV is present in both.
  19. 19.  manifests as vesicular lesions clustered within 1 or 2 adjacent dermatomes  rash is mild, with new lesions appearing for a few days  Herpes zoster in children tends to be milder than disease in adults  It occurs more frequently & disease is more severe if-  Children is on immunosuppressive therapy  HIV infected children.  postherpetic neuralgia is very unusual in children.  Transverse myelitis with transient paralysis is a rare complication of herpes zoster
  20. 20. Herpes zoster involving the lumbar dermatome.
  21. 21. Varicella in Vaccinated Individuals (“Breakthrough Varicella”)  One dose of varicella vaccine is >97% effective in preventing severe varicella  85% effective in preventing all disease after exposure to wild-type VZV.  Breakthrough disease is varicella that occurs in a person vaccinated >42 days before rash onset and is caused by wild-type VZV
  22. 22.  rash occurring < 14 days after vaccination was most commonly wild-type VZV  Rash occurring 14-42 days after vaccination was due to either  Wild-type VZV-------- breakthrough varicella  vaccine strains---------vaccine-associated rash  ????????
  23. 23.  The Breakthrough varicella rashes are  atypical  predominantly maculopapular  vesicles are seen less commonly  illness is most commonly mild with <50 lesions  shorter duration of rash  Less contagious  Complications are less  little or no fever
  24. 24. Progressive Varicella  Progressive varicella, is a severe complication of primary VZV infection.  visceral organ involvement  coagulopathy  severe hemorrhage  Continued new vesicular lesion development  Severe abdominal pain
  25. 25.  appearance of hemorrhagic vesicles  the risk for progressive varicella  congenital cellular immune deficiency disorders  Malignancy  organ transplantation  Pt. is on steroid therapy  Unusual clinical findings  develop a unique hyperkeratotic appearance  continued new lesion formation for weeks or months
  26. 26. Neonatal Varicella Infants whose mothers demonstrate varicella in the period from 5 days prior to delivery to 2 days afterward are at high risk for severe varicella.  The infant acquires the infection transplacentally  The infant's rash usually occurs toward the end of the 1st week to the early part of the 2nd week of life  maternal immunoglobulin G (IgG) is able to cross the placenta if delivery occurs after 30 wk of gestation  ?????
  27. 27.  Newborns whose mothers demonstrate varicella 5 days before to 2 days after delivery should receive 1 vial of VariZIG as soon as possible.  All premature infants born <28 wk gestation to a mother with active varicella at delivery (even if the maternal rash has been present for >1 wk) should receive VariZIG  intravenous immune globulin (IGIV) may provide some protection  the infant should be treated with acyclovir (10 mg/kg every 8 hr IV) when lesions develop.  prognosis is good if pt. receive prompt antiviral therapy 
  28. 28. Congenital Varicella Syndrome  In Utero Transmission  Risk of infection (No disease)  Early part of pregnency- 25%  Risk of CVS ( Disease)  Before 13 wks of gestation – 0.4%  In between 13 – 20 wks - 2%
  29. 29. CVS Manifestations Organ/ System Manifestations Skin Cicatricial skin scarring LIMB Limb hypoplasia NEUROLOGIC Microcephaly, cortical atrophy, seizures, and mental retardation EYE Chorioretinitis, microphthalmia, and cataracts RENAL Hydroureter and hydronephrosis ANS Neurogenic bladder, swallowing dysfunction, and aspiration pneumonia
  30. 30. Diagnosis of CVS Fetopathy  The diagnosis of VZV fetopathy is based mainly on the  history of gestational varicella  presence of characteristic abnormalities in the newborn infant  viral DNA may be detected in tissue samples by PCR.  VZV-specific IgM antibody is detectable in the cord blood  Chorionic villous sampling
  31. 31. Diagnosis of varicella  Laboratory evaluation has not been considered necessary  Leukopenia  relative and absolute lymphocytosis.  liver function tests are mildly elevated  CSF in CNS complications  mild lymphocytic pleocytosis  moderate increase in protein content
  32. 32.  Rapid laboratory diagnosis  direct fluorescence assay  rapid culture with specific immunofluorescence staining  PCR amplification testing  multinucleated giant cells can be detected with nonspecific stains Tzanck smear  VZV IgG antibodies:- Rise > 4 fold ???  Testing for VZV IgM antibodies is not useful
  33. 33. Treatment in Varicella Acyclovir therapy is Not Recommended Routinely for treatment of uncomplicated varicella in the otherwise healthy child the marginal benefit the cost of the drug low risk for complications of varicella.
  34. 34. Oral Acyclovir Theraphy  Oral acyclovir in  children >12 mo of age with  chronic cutaneous or pulmonary disorders  Pt. Is on corticosteroid therapy  individuals receiving long-term salicylate therapy  Possibly Secondary cases among household contacts ??  Nonpregnant individuals > 13 years of age  Dose – 20mg/Kg/ Dose QID for 5 days  Within 24 Hours of onset of exenthem
  35. 35. Intravenous Acyclovir therapy  Varicella with severe disease/ complicated cases  pneumonia  severe hepatitis  thrombocytopenia  encephalitis  varicella in immunocompromised patients  Dose:- IV acyclovir (10 mg/Kg/ Dose or 500 mg/m2 every 8 hr IV) continued for 7–10 days  To be given even after > 72 Hours of Rash onset  Other molecules  famciclovir  Valacyclovir  Acyclovir-resistant VZV:- intravenous foscarnet ( 120 mg/kg/day TDS for upto 3 Wks)
  36. 36. Treatment in Herpes Zoster  uncomplicated HZ in children - antiviral agent may not always be necessary  herpes zoster in immunocompromised  Acyclovir (500 mg/m2 or 10 mg/kg every 8 hr IV). Adults-  Acyclovir 800 mg 5 times a day for 5 days  Famciclovir 500 mg TDS for 7 days  Valacyclovir 1000 mg TDS for 7 days  Use of corticosteroids in the treatment of herpes zoster in children is not recommended but can be given in elderly to improve quality of life.
  37. 37. Complications  more common in immunocompromised patients  In healthy child, mild varicella hepatitis is relatively common  Mild thrombocytopenia occurs in 1-2%  Other Complications  Bacterial Infections  Encephalitis and Cerebellar Ataxia  Pneumonia  Nephritis and Nephrotic Syndrome  HUS  Arthritis  Mycocarditis  Pericarditiis  Pancreatitis and Orchitis
  38. 38. Bacterial Infections  Secondary bacterial infections of the skin  group A streptococci and S. aureus  occur in up to 5% of children  impetigo  cellulitis  lymphadenitis  subcutaneous abscesses.  manifestation of secondary bacterial infection  erythema of the base of a new vesicle.  Recrudescence of fever 3-4 days after the initial exanthem
  39. 39.  Other invasive complications  varicella gangrenosa  bacterial sepsis  pneumonia  arthritis  osteomyelitis  cellulitis  necrotizing fasciitis  toxic shock syndrome
  40. 40. Encephalitis and Cerebellar Ataxia  morbidity from CNS complications is highest among patients < 5 yr  Nuchal rigidity  altered consciousness  seizures  gait disturbance  nystagmus, and slurred speech  Neurologic symptoms usually begin 2-6 days after the onset of the rash.  Clinical recovery is rapid and is usually complete in 24-72 hrs
  41. 41. Pneumonia  Respiratory symptoms, which may include  cough  dyspnea  cyanosis  pleuritic chest pain  hemoptysis
  42. 42. EVIDENCE OF IMMUNITY TO VARICELLA Evidence of immunity to varicella consists of any of the following: Documentation of age-appropriate vaccination with a varicella vaccine: • Preschool-aged children (i.e., aged >12 mo): 1 dose • School-aged children, adolescents, and adults: 2 doses Lab evidence of immunity or laboratory confirmation of disease Diagnosis or verification of a history of varicella disease/ herpes zoster by a health-care provider
  43. 43. Post exposure Prophylaxis Vaccine:- given to healthy children within 3-5 days after exposure ( ASAP) High-titer anti-VZV immune globulin is recommended - immunocompromised children - pregnant women without evidence of immunity - newborns exposed to varicella - Close contact b/w susceptible high risk patient and patient of HZ - 1 vial / 125 Units .....per 10 Kg - Max 625 Units New Borns :  < 28 wks gestation, exposed to varicella, regardless of maternal immunity  >28 wks gestation, exposed to varicella, no evidence of maternal immunity Adults – IG G titre to be done before anti VZV IG
  44. 44. Take Home Msgs  Identification of Disease  Laboratory Investigations  Treatment and Supportive t/t  Early identification of complications and management  Post exposure prophylaxis counselling  Syp Acyclovir 400mg/ 5ml , Zovirex 200 Rs  Tab Acyclovir 200 400 600 800 (146/ 5 Tab)  Inj Acyclovir , 250 mg , 246 Rs  Vaccine Rs 1700
  45. 45. Thanks….

×