viral exanthems

• measle (rubeola)

  • common, contagious
  • in children and young adult
  • paramyxovirus family
  • enveloped, single stranded RNA genome
  • hemagglutinin (h antigen) and fusion protein (f protein)
  • inhalation of respiratory droplet
  • most contagious during prodromal period
• clinical findings for measle

  • high grade with 3c's and photophobia
  • koplik's spot
  • maculopapular rashes - undergoes desquamation
  • fever persist as rashes appear
  • fever subsides after all rashes appears
• treatment for measle

  • live attenuated vaccine with mumps and rubella (2 years old)
  • immune globulin (exposed individual)
• rubella (germal measle)

  • benign infection (children) ; more sever in adult
  • single stranded RNA
  • rubivirus and togaviridae family
  • inhalation of respiratory droplet, transplacental transmission
• clinical findings of rubella

  • "three days measle"
  • fever > maculopapular rashes
  • rashes are puritic
  • forccheimer spot may be present in palate
• congenital rubella - most serious outcome
• diagnosis of rubella is through anti rubella specific igM
• treatment for rubella

  • MMR vaccine - 2 years old
• roseola infantums (sixth disease)

  • caused by HHV6 ; herpesviridae
  • infects lymphocyes ; CD4+T
  • virus replicates in salivary glands
  • cause of febrile seizure in children
• erythema infectiosum (fifth disease)

  • cause by parvovirus B19
  • single stranded DNA - parvoviridae (smalles)
  • common in early school age children
  • targets progenitor cell (lysis)
  • respiratory droplet and oral secretion, blood transmission, vertical transmission
• clinical finding of fifth disease

  • biphasic infection - lytic and immunologic stage
  • lytic stage: mild sign of upper respiratory tract infection, most contagious
  • immunologic stage: lace-like rash (face) and arthralgia
  • B19 in adults: polyarthritis (anemic) and hydrops fetalis (pregnant)
  • disgnosis through ELISA and polymerase chain reaction
• varicella (chickenpox)

  • benign, self-limiting in children ; severe infection in adult
  • varicella-zoster virus - double stranded enveloped DNA ; herpesviridae
  • infects mucoespithelial cells
  • inhalation of respiratory droplets, direct contact with lesion
• clinical finding of chickenpox

  • fever and vesicular eruption
  • maculopapular rashes > vesicular with pruritus (ruptures) > ulcerate > crust
  • do not leave scars and is superficial
  • pneumonia in adult and encephalitis in children
• diagnosis for chickenpox

  • tzanck smear of skin scraping

  treatment

  • acyclovir - doent prevent latency
  • varicella zoster virus vaccine - for prevention
• herpes zoster (shingles)

  • occurs in adult or immunocompromised
  • reactivation of chickenpox
  • thoracic dermatome
  • post-herpetic neuralgia - prolonged pain that persist for months
• variola (smallpox)

  • contagious ; high fatality rate
  • variolation - immunization
  • variola virus ; poxviruses - largest DNA virus
  • through inhalation, direct contact
  • treatment: methisazone