Herpes Zoster Opthalmicus

Question 1

HZO is the reactivation of the varicella- zoster virus in what area?

Answer 1

The area supplied by the ophthalmic division of the trigeminal nerve

Question 2

What features are associated with HZO?

Answer 2

Vesicular rash around the eye, which may or may not involve the eye itself
Hutchinson’s sign - rash on tip or side of nose, which indicates nasociliary nerve involvement (branch of ophthalmic nerve) = a strong indicator for ocular involvement

Question 3

What does Hutchinson’s sign indicate?

Answer 3

Nasociliary involvement

Strong risk factor for ocular involvement as the nasociliary nerve also supplies the globe of the eye

Question 4

How is it managed?

Answer 4

Oral anti viral treatment 7-10 days
IV if severe or immunocompromised
Topical corticosteroids to treat secondary inflammation of eye
Ocular involvement requires urgent opthalmology review

Question 5

Varicella zoster virus has 2 distinct forms. What are they?

Answer 5

First occurring in childhood as chickenpox (varicella)
Then lies dormant in the sensory ganglia for years until in 20% of individuals it reactivates and spreads across a dermatome as shingles (zoster)

Question 6

Shingles typically affects what age group?

Answer 6

More than 50 years old

Question 7

What are the most common sites of shingles?

Answer 7

Thoracic nerves 55%

Ophthalmic branch of the trigeminal nerve 20%

Question 8

How does ophthalmic shingles present?

Answer 8

Pain and neuralgia in the distribution of the ophthalmic division of CN5 dermatome - precedes a blistering and inflamed rash

Question 9

What is the most common complication of ophthalmic shingles?

Answer 9

Post herpatic neuralgia

Others: conjunctivitis, keratitis, episcleritis, ptosis

Question 10

What is neuralgia ?

Answer 10

Stabbing, burning pain due to an irritated or damaged nerve

Question 11

In many cases of HZO, a prodromal period occurs - what symptoms does this include?

Answer 11

Period of fever, malaise, eye pain prior to eruption of the skin rash

Question 12

What are the main predisposing factors?

Answer 12

Age

Immunocompromised

Question 13

What ocular symptoms can occur during the acute phase?

Answer 13

Discharge
Redness
Pain
Photophobia

Question 14

What skin features can occur?

Answer 14

Unilateral painful, red, vesicular rash on forehead and upper eyelid, progressing to crusting after 2-3 weeks resolution can involve scarring
Periorbital oedema
Lymphadenopathy- swollen regional lymph nodes
Hutchinson’s sign

Question 15

What ocular lesions can occur?

Answer 15

Mucopurulent conjunctivitis 
Keratitis 
Reduced corneal sensation 
Episcleritis 
Scleritis - less common 
Anterior uveitis 
Secondary glaucoma 
Rare - posterior segment involvement e.g retinitis

Question 16

What are some differentials?

Answer 16

Herpes simplex keratitis (dendritic ulcer)
Atopic eczema
Impetigo 
Contact dermatitis 
Cellulitis

Question 17

Who should see a specialist?

Answer 17

If nose tip involved
Ocular involvement
The eye turns red within 3 days - need to exclude anterior uveitis

Question 18

When do oral antivirals improve symptoms?

Answer 18

If given within 72 hours of rash onset or if new vesicles still forming