The chickenpox

A family story

Index Case Michaelmas Term Year 2

The case

• Little Lizzie (aged 3) caught chickenpox at nursery school

Her 44 year old father gave her a cuddle:

Then….• 2 weeks later he started to feel unwell with

a headache and temperature• Shortly afterwards he developed a

generalised maculo-papular rash• The rash developed into numerous vesicles,

particularly on the face and trunk• He also developed a cough• T39C, P120/min• His wife told him not to pick his spots, even

though they were itchy

Then..

• After 4 days his temperature began to fall.

• A woman from the man’s office is worried as she is ten weeks pregnant and was working with the man on the day he became ill

What is chickenpox?

chickenpox• Primary infection with varicella zoster

(DNA virus). Caught from respiratory droplets and fomites

pathology

• Caught through respiratory mucosa• 10-12 day prodromal stage• Virus spreads from lungs to lymphocytes

and monocytes• 2nd viremia occurs and virus travels to

epithelial surfaces• Papules contain multinucleated cells with

intracellular inclusions• Spread from respiratory tract or ruptured

papillae: contagious 12-14 days after infection

Why did the man get it but not his wife?

She was immune, he wasn’t

• Previous infection provides a high degree of immunity

Why should he avoid picking his spots, and why did they itch?

• Scratching breaks the skin and encourages secondary infection with bacteria such as staph. Aureus. This promotes scarring

• Itch is a symptom related to any inflammatory response.

• Itching can be caused by a variety of skin disorders (e.g. eczema)

• Also generalised medical conditions, e.g renal failure; liver failure

Could the man die of his infection?

yes• Around 50 deaths/year in USA.

• Usually secondary to pneumonia

• Risk higher in immunosuppressed

What could be done to treat him?

Management of chickenpox

• Supportive

• VZIG: varicella zoster immunoglobulin

• Acyclovir: reduces duration of fever if given within 24 hours of developing a rash

• Avoid contact with others at risk until last vesicle crusted over

What should the pregnant woman do?

Exposure to HZ in pregnancy• Has she already had chickenpox? Most

women in UK have

• If uncertain measure antibodies

• If not immune give ZIG

• Small risk of teratogenesis 1-2% in first 20 weeks pregnancy

• Infection near fullterm- risk of neonatal encephalitis

Will the man have any further problems from chickenpox?

shingles

• A vesicular rash in dermatomal distribution

• Reactivation of varicella zoster in dorsal root or cranial nerve ganglia

• More common in elderly, immunosuppressed or with concurrent illness

Is there a case for vaccination?

HZ vaccination

• Live attenuated virus

• Available in USA

• May be a case in seronegative if planning pregnancy?

And finally- why is vaccination called vaccination?

In 1796 Edward Jenner injected cowpox from Sarah Nelmes into

James Philip