Varicella-Zoster Flashcards
What family?
Herpesvirus
How many serotypes?
1
What are the 2 diseases it causes?
- Varicella (chickenpox) - primary illness
- Zoster (shingles) - recurrent manifestation of infection
What are the clinical presentations of varicella?
- Fever
- Crops of vesicles in waves and more on trunk than extremities (centripetal distribution)
Usually more severe symptoms in adults than children
What are the complications of varicella?
- Skin infection (staphylococci/streptococci)
- Aseptic meningitis
- Neurological syndrome
- Post-infectious encephalomyelitis (one week after rash)
- Pneumonia (cough, dyspnoea, hypoxia, diffuse nodular infiltrate, pulmonary calcification - may be fatal)
- Haemorrhagic (thrombocytopenia, DIVC)
- Arthritis
- Congenital varicella (rare transplacental infection in neonates born to mothers with varicella in early pregnancy)
- Neonatal varicella
- Overwhelming varicella (immunosupressed patients)
How to treat varicella?
- Symptomatic (antipyretics, antipruritics)
- Varicella-zoster immune globulin (VZIG) prophylaxis in exposed high-risk immunocompromised children
- Acyclovir (severe varicella pneumonia/haemorrhagic varicella)
How is varicella transmitted?
- Nose and mouth by droplet infection from infectious saliva
- Contact with skin lesions of varicella cases
How to control varicella?
- Barrier nursing and isolation of immunosupressed patients
- VZIG prophylaxis
- Live attenuated vaccine for high-risk patients and even healthy subjects
Where does zoster take place? How does zoster come about?
- Recrudescent disease occuring in dermatome of sensory nerve ganglion
- Reactivation of latent VZV (usually long period after childhood varicella, more frequent in old age and immunocompromised)
What are the clinical presentations of zoster?
Painful vesicular eruption morphologically similar to varicella
What is the skin distribution of zoster?
- 50%: thoracic
What are the complications of zoster?
- Encephalomyelitis (lymphocyctic pleocytosis in CSF)
- Post-herpetic neuralgia (often in elderly)
- Disseminated zoster (vesicles outside involved dermatomes in immunosupressed)
What is the treatment of zoster?
Acyclovir IV (can limit progression of zoster if given early, even in immunocompromised)
How to prevent zoster?
Zoster vaccine for >50y/o
Who does zoster mostly occur in?
Mainly adults
