Herpes zoster (shingles)

Question 1

Cranial nerve involvement

Answer 1

The trigeminal nerve—15% of all cases:

• ophthalmic branch—50% affects nasociliary branch with lesions on tip of nose and eyes (conjunctivae and cornea)
• maxillary and mandibular—oral, palatal and pharyngeal lesions

The facial nerve: lower motor neuron facial nerve palsy with vesicles in and around external auditory meatus

• (notably posterior wall)—the Ramsay–Hunt syndrome.

Question 2

Management

Answer 2

Appropriate detailed explanation and reassurance.

Dispel myths.

Explain that herpes zoster is only mildly contagious but children can acquire chickenpox after exposure to a person with the disorder.

Question 3

Topical treatment

Answer 3

For the rash, use a drying lotion such as menthol in flexible collodion.

Aciclovir ointment can be used but it tends to sting.

Question 4

Oral medication

Answer 4

Analgesics (e.g. paracetamol + ibuprofen co)

Guanine analogue antiviral therapy for:

–all immunocompromised

–any pt provided rash present <72 h (esp. those >60 yrs)

–ophthalmic zoster (evidence to date—reduces scarring and pain but not neuralgia)

–severe acute pain

Question 5

Drugs and dosage

Answer 5

Aciclovir 800 mg 5 times daily for 7 d or

Famciclovir 250 mg 8 hrly for 7 d or

Valaciclovir 1 g 8 hrly for 7 d

Question 6

Postherpetic neuralgia

Answer 6

Definition: pain persisting >4 weeks after vesicles crusted.

Increased incidence with:

• age and debility
• duration greater than 6 mths.

Resolves within 1 yr in 70–80% but in others it may persist for years.

Eye complications of ophthalmic zoster, including keratitis, uveitis and eyelid damage.

Question 7

Treatment options

Answer 7

Oral medication

Basic analgesics (aspirin or paracetamol or NSAID or combination orally)

Tricyclic antidepressants (e.g. amitryptiline 10–50 mg (o) nocte starting dose, to maximum 100 mg nocte) or

Gabapentin 300 mg (o) daily (nocte) initially ↑ as tolerated to tds or

Pregabalin (for lancinating pain) 75 mg (o) nocte initially ↑ as tolerated

Topical medication

Capsaicin (Capsig) cream.

• Apply the cream, which can ‘burn’, to the affected area 3–4 times/d
• (apply ice massage, 20 mins before).

Lignocaine 5% ointment or 10% gel or

Lignocaine 5% patch to painful area

Others

TENS as often as necessary (e.g. 16 h/d for 2 wks) plus antidepressants.

Question 8

Prevention

Answer 8

A single varicella zoster vaccine is recommended for adults (not immunocompromised) aged 60 years and over.

It has been part of the National Immunisation Program for those up to 79 years

Consider giving varicella zoster immune globulin to contacts of patients who are immunosuppressed and have no history of varicella (vaccine ‘Zostavac’).