This is caused by the chickenpox virus and may cause severe local infection complicated by secondary bacterial infection - usually S. aureus or S. pyogenes.
It may occur in any dermatome.
Aciclovir treatment improves the rate of recovery and reduces post-herpetic neuralgia only if started within 72 hours of onset. Best results follow earliest possible treatment.
All patients with ocular herpes or immune suppression should be treated with aciclovir.
Steroids may lead to faster healing, but no change to the incidence of post-herpetic neuralgia.
There are a number of strategies for reducing/managing post-herpetic neuralgia including low dose amitriptyline and gabapentin. Gabapentin requires Special Authority if continued on discharge. A tricyclic must have been trialled prior to gabapentin for Special Authority to be granted.
Diagnosis:
Clinical.
If in doubt, send samples of fluid and cells taken from ulcer base with a cotton swab in viral transport media for PCR.
Treatment:
Normal host:
Aciclovir 800 mg PO 5 times daily for 7 days.
Immunocompromised host:
Not severe - as for normal host.
Severe (more than one dermatome, dissemination) aciclovir 10 mg/kg IV q8h 7-14 days.
Ocular zoster:
Aciclovir 800 mg PO 5 times daily and consult an Ophthalmologist.
Sight-threatening disease aciclovir 10 mg/kg IV q8h.