Herpes simplex / Cold sores

Question 1

Herpes simplex virus: manifestations and complications

Answer 1

Examples of manifestations

• Herpes labialis (synonyms: fever blisters, cold sores)
• • Keratoconjunctivitis, including dendritic ulcer
• Genital infection
• Other areas of skin, such as buttocks

Complications

• Eczema herpeticum
• Erythema multiforme (3–14 d postinfection), often recurrent
• Myeloradiculopathy with genital herpes
• Pneumonia
• Encephalitis

Question 2

Herpes labialis (classical cold sores)

Answer 2

The objective is to limit the size and intensity of the lesions.

Topical treatment

At the first sensation of the development of a cold sore (preferably at the prodrome stage):

apply an ice cube to the site for up to 5 mins every 60 mins (for first 12 h) or

other topical applications include:

• idoxuridine 0.5% preparations (Herplex D liquifilm, Stoxil topical, Virasolve) applied hrly day 1 then 4 hrly or
• povidone-iodine 10% cold sore paint: apply on swab sticks 4 times a day until disappearance or
• aciclovir 5% cream or penciclovir 1% cream, 4 hrly while awake for 4 d

Question 3

Oral treatment

Answer 3

Oral treatment for severe attack, one of:

• famciclovir 500 mg (o) bd for 7 d
• valaciclovir 1 mg (o) bd for 7 d
• aciclovir 400 mg (o) 5 times/d for 7 d
• Aciclovir can be used in children.

Oral treatment for recurrent episodes, one of:

• aciclovir 400 mg (o) 5 times/d for 5 d
• famciclovir 1500 mg (o) as a single dose
• valaciclovir 2g (o) bd for 1 d

Question 4

Prevention

Answer 4

If exposure to the sun precipitates the cold sore, use a 30+ sun protection lip balm, ointment or solastick.

Zinc sulphate solution can be applied once a wk for recurrences.

Oral aciclovir 400 mg bd or valaciclovir 500 mg/d (6 mths) can be used for severe and frequent recurrences (>6/yr)

Question 5

Genital herpes

Answer 5

Topical treatment

Pain relief can be provided in some patients with topical lignocaine 2% gel.

Saline baths and analgesics are advisable.

Question 6

Oral treatment

Answer 6

For the first episode of primary genital herpes (preferably within 24 h of onset) one of the guanine analogues can be used.

• aciclovir: 400 mg 3 times/d for 5–10 d or until resolution of infection or
• famciclovir: 250 mg (o) tds for 5–10 d or
• valaciclovir: 500 mg (o) bd for 5–10 d

This appears to reduce the duration of the lesions from 14 days to 5–7 d.

The drugs are not usually used for recurrent episodes, which last only 5–7 d.

A 5-d course of any of the drugs can be used for a severe recurrence.

Very frequent recurrences (≥6 in 6 mths) benefit from continuous low-dose therapy for 6 mths

• e.g. valaciclovir 500 mg (o) once daily

Question 7

Eczema herpeticum

Answer 7

Aciclovir 400 mg (o), 5 times/d or

Famciclovir 500 mg (o) bd or

Valaciclovir 1 g (o) bd until healed.

Use IV aciclovir for severe cases.

Question 8

Herpetic whitlow

Answer 8

Drugs and dosage as above for 7–10 d.

Question 9

Herpes simplex keratitis

Answer 9

Aciclovir 3% ophthalmic ointment, 5 times/d for 14 d

• or at least 3 d after healing also

Atropine 1% 1 drop 12 hrly

Specialist referral recommended.