A8. Skin diseases caused by varicella zoster virus

Varicella

• Varicella (chickenpox)
  • Primary infection during childhood
  • Lasts 6 days in immunocompetent persons
  • Transmission
    • Highly contagious
    • Airborne transmission
    • Incubation period 2 weeks
  • Clinical features
    • Lesions covering the entire body
    • Severe pruritus
    • Macules -> papules -> vesicles with erythematous base -> crusts
      • All of these stages are present simultaneously, which is a hallmark for the disease
    • Fever
  • Virus remains latent in sensory ganglia
  • Diagnosis
    • Clinical -> characteristic rash
    • Tzanck smear, PCR
  • Treatment
    • For pruritus
      • Calamine lotion
      • Pramoxine gel
      • Oral antihistamines
    • Therapy
      • Only for severe cases or high-risk groups (adults, immunosuppressed)
      • Acyclovir
      • Post-exposure prophylaxis
        • Active immunization (vaccine)
        • Passive immunization (immunoglobulins)
  • Prevention
    • Vaccination
  • Complication
    • Bacterial superinfection
      • Impetigo
      • Phlegmon
    • Scarring
    • Congenital varicella syndrome (if chickenpox during pregnancy)

Shingles

• Shingles (herpes zoster)
  • Reactivation
  • Older patients
  • Triggers
    • Immunosuppression
    • Advanced age
    • Malignancy
    • Malnutrition
  • Clinical features
    • Erupts in dermatome pattern
    • Severe pain
    • Erythematous maculopapular rash -> vesicles -> rupture
  • Complications
    • Herpes zoster oticus
      • Herpes in facial and vestibulocochlear nerve
      • Blindness
    • Herpes zoster ophthalmicus
      • Herpes in ophthalmic part of trigeminal nerve
      • Facial paresis
      • SN hearing loss
    • Post-herpetic neuralgia
    • Herpes zoster encephalitis
  • Diagnosis
    • Clinical -> characteristic rash
  • Treatment
    • Wet dressing with aluminium acetate
    • 5 x 800mg acyclovir for 10 days
    • NSAIDs