Chickenpox

B01.9/B01.8

DESCRIPTION

A mild viral infection that presents 2–3 weeks after exposure, with:

  • mild fever preceding the rash
  • lesions beginning on the trunk and face, later spreading to the arms and legs
  • small, red, itchy spots that turn into blisters and crusts. These stages may all be present at the same time.

Chickenpox is infective from the start of the fever until 6 days after the lesions have appeared or until all the lesions have crusted.
The infection is self-limiting, with a duration of about 1 week.
Complications such as secondary bacterial infection, encephalitis, meningitis and pneumonia may occur (more common in adults and immunocompromised patients).

GENERAL MEASURES

  • Isolate from immunocompromised people and pregnant women until all lesions have crusted.
  • Ensure adequate hydration.
  • Cut fingernails short and discourage scratching.

MEDICINE TREATMENT

CAUTION
Avoid the use of aspirin in children and adolescents < 16 years of age with acute febrile illness because of risk of Reye’s syndrome.

For itch:

  • Calamine lotion, applied as needed.

In severe cases

Children

CAUTION
Do not give an antihistamine to children < 2 years of age.

Adults

  • Chlorphenamine, oral, 4 mg, 6–8 hourly.

For fever with distress:

Children

Adults

  • Paracetamol, oral, 1 g 4–6 hourly when required to a maximum of 4 doses per 24 hours.
    • Maximum dose: 15 mg/kg/dose.
    • Maximum dose: 4 g in 24 hours.

If skin infection is present due to scratching, treat as for bacterial skin infection. See Bacterial infections of the skin

Treatments with antiviral agents are recommended for:

  • Immunocompromised patients.
  • All patients with severe chickenpox (irrespective of duration of rash).
    • Extensive rash.
    • Visceral involvement.
    • Haemorrhagic rash.
    • Presence of complications.
  • Adults and adolescents presenting within 48 hours of the onset of the rash.
  • Pregnant women.

Children

  • Aciclovir, oral, 20 mg/kg/dose 6 hourly for 7 days (Doctor prescribed).
Weight
kg 		Dose
mg 		Use one of the following: Age
months/years
Susp
200 mg /5 mL 		Tablet Tablet
200 mg 400 mg
>3.5–5 100 2.5 mL – – >1–3 months
>5–7 140 3.5 mL – – >3–6 months
>7–9 160 4 mL – – >6–12 months
>9–11 200 5 mL 1 tablet ½ tablet >12–18 months
>11–14 240 6 mL – – >18 months–3 years
>14–25 300 7.5 mL 1½ tablet – >3–5 years
>25–35 500 15 mL 2 ½ tablets – >7–11 years
>35–55 700 – 3 ½ tablets – >11–15 years

Adults

  • Antiviral, (active against varicella zoster) e.g.:
    • Aciclovir, oral, 800 mg 6 hourly for 7 days (Doctor prescribed).

LoEIII [1]

REFERRAL

  • Complications such as:
    • meningoencephalitis
    • pneumonia
  • Severely ill patients.
  • Pregnant women.
  • Asymptomatic neonates whose mothers had developed chickenpox during the period from 7 days before to 7 days after delivery.
  • Neonates with clinical chickenpox.