Questionnaire/history: Prodrome? - Nausea? - Myalgia? - Anorexia? - Headache?

- Fever? - Malaise? - Loss of appetite? - Feeding problems? Itensely itchy skin lesions?

Past medical history?

Current medication?

Known drug allergies?

Examination: Small, erythematous macules? Papules?

Clear vesicles Pustules (within 24 hours)? Crusting lesions (usually within 5 days)?

Location of lesions (eg on the scalp, face, trunk or proximal limbs)

Complications? Children: - Secondary bacterial skin infection (with erythema, tenderness and new fever after initial improvement)? - Reye’s syndrome? - Encephalitis? - Myocarditis? - Glomerulonephritis?

Adults (more serious infection): - Pneumonia? - Hepatitis? - Encephalitis?

Management:

Advised:

Calamine lotion Paracetamol

Antihistamine

To avoid NSAIDs as they are associated with increased rates of severe skin infections and aspirin (especially in children < 16 years)

To avoid contact with immunocompromised, pregnant women, infants 4 weeks old or less.

Nursery/school exclusion until all the vesicles have crusted over

Considered oral acyclovir 800 mg 5x daily 7/7 for adults or adolescents (14y+) who present within 24h of rash developing (this is based on expert opinion given the increased rates of complications in older people - evidence is lacking it actually improves outcomes) AND one of: severe pain, dense/oral rash, taking steroids, smoker?

(Note: Prescribe aciclovir particularly for those at higher risk of poor outcomes eg smokers, those with severe lung or cardiovascular disease, and those with chronic skin disorders.

Not recommended in otherwise healthy children.)

If serious complications admit to hospital.

Pregnant women - primary infection

Admit to hospital if suspected chickenpox and illness such as respiratory or neurological symptoms (excluding headache), haemorrhagic rash or bleeding, severe disease, immune suppression.

For all other women seek specialist advice on further management - oral antivirals should only be prescribed in primary care with specialist advice.

Oral aciclovir may be prescribed particularly if presenting < 24 hours from the development of rash and is 20 weeks gestation or greater. In women <20/40 aciclovir should be used with caution, but a US registry of 1st-trimester aciclovir exposure (N~600) shows no increased risk.

~1% risk of developing fetal varicella syndrome with infection if <28/40.

Where primary care management is advised by a specialist, careful safety netting is required and close monitoring, i.e. daily review and if this is not possible in primary care admission should be considered.

Women need to be admitted if fever persists, or new/persistent rash develops after 5/7.

Neonates whose mothers develop infection 7 days before or after delivery will be given varicella-zoster immunoglobulin (VZIG)

Breastfeeding women - primary infection:

Consider aciclovir if presenting within 24 hours of rash development.

Seek specialist advice about whether to continue breastfeeding and if the baby requires treatment to minimise complication risk.

HPA advice is mothers should be allowed to breastfeed, but where lesions are close to the nipple expressing milk is advised, which can be used if the baby is covered by VZIG or aciclovir.

Pregnant women – exposure:

Significant exposure?

Within 48 hours of rash developing until crusting (including disseminated zoster, exposure localised lesions or immunosuppressed with shingles)?

Continuous home contact, in the same room for 15 minutes?

Face-to-face contact eg having a conversation?

If a definite history of chickenpox or shingles then women can be reassured she is not at risk.

If no or uncertain history of chickenpox and significant exposure then establish gestation and seek immediate specialist advice and check bloods for varicella-zoster virus immunoglobulin (VZV IgG) if able to get results within 1-2 days (HPA algorithm)

If detected reassure, and advise review if a rash develops.

If negative discuss urgently with specialist - requires VZIG within 10/7 of 1st exposure - needs review if a rash develops.

The woman should be advised she is potentially infectious for 8-28 days after contact.

If further exposure after 3 weeks, VZIG may be repeated.

Consider vaccination after the pregnancy.

To seek immediate specialist advice for neonates < 4 weeks old and those immunocompromised.

Neonates:

Neonates whose mothers develop infection 7 days before or after delivery will be given varicella-zoster immunoglobulin (VZIG)

Resource(s):

NICE CKS: Chickenpox NICE/Public Health England: Summary of antimicrobial prescribing guidance – managing common infections