Herpes Zoster Ophthalmicus

Question 1

What is herpes zoster ophthalmicus (HZO)?

Answer 1

A reactivation of the varicella-zoster virus in the ophthalmic division of the trigeminal nerve.

Question 2

What causes herpes zoster ophthalmicus?

Answer 2

Reactivation of latent varicella-zoster virus (chickenpox) in the trigeminal ganglion.

Question 3

What are the key symptoms of HZO?

Answer 3

Painful rash on the forehead, eyelid, or nose, along with redness, swelling, and potential vision changes.

Question 4

What is Hutchinson’s sign?

Answer 4

The presence of vesicles on the tip or side of the nose, indicating nasociliary nerve involvement and a higher risk of ocular complications.

Question 5

What is the pathophysiology of HZO?

Answer 5

Reactivation of the virus causes inflammation and damage to the skin, cornea, and other ocular structures.

Question 6

What are the risk factors for HZO?

Answer 6

Increasing age, immunosuppression, stress, and previous chickenpox infection.

Question 7

What are the stages of the rash in HZO?

Answer 7

Initially erythematous macules, followed by vesicles, pustules, and crusting over time.

Question 8

What is the typical distribution of the rash in HZO?

Answer 8

It follows the dermatome of the ophthalmic branch of the trigeminal nerve, typically unilateral.

Question 9

What are common ocular complications of HZO?

Answer 9

Keratitis, uveitis, conjunctivitis, scleritis, optic neuritis, and secondary glaucoma.

Question 10

What is the significance of early treatment in HZO?

Answer 10

Early antiviral therapy reduces the risk of complications and severity of the disease.

Question 11

What antivirals are used to treat HZO?

Answer 11

Oral aciclovir, valaciclovir, or famciclovir.

Question 12

What is the typical duration of antiviral therapy in HZO?

Answer 12

Usually 7–10 days.

Question 13

What is the role of topical corticosteroids in HZO?

Answer 13

To reduce inflammation in cases of keratitis or uveitis, prescribed by an ophthalmologist.

Question 14

What is post-herpetic neuralgia (PHN)?

Answer 14

Persistent pain in the affected dermatome after the rash has resolved, a common complication of HZO.

Question 15

What is the role of analgesia in HZO?

Answer 15

Pain relief with paracetamol, NSAIDs, or sometimes neuropathic pain agents like amitriptyline or gabapentin.

Question 16

What are the differential diagnoses for HZO?

Answer 16

Herpes simplex virus (HSV) infection, cellulitis, contact dermatitis, and bacterial conjunctivitis.

Question 17

What is the role of vaccination in preventing HZO?

Answer 17

The shingles vaccine (e.g., Zostavax, Shingrix) reduces the risk of developing HZO, especially in older adults.

Question 18

What are the signs of corneal involvement in HZO?

Answer 18

Punctate epithelial keratitis, stromal keratitis, or corneal ulceration.

Question 19

What investigations are needed for suspected HZO?

Answer 19

Diagnosis is usually clinical, but PCR or direct fluorescent antibody testing can confirm varicella-zoster virus.

Question 20

What is the prognosis for HZO with treatment?

Answer 20

With prompt antiviral therapy, most patients recover, but some may have persistent visual or neurological complications.

Question 21

What are systemic complications of HZO?

Answer 21

Post-herpetic neuralgia, cranial nerve palsies, and, rarely, encephalitis or stroke.

Question 22

How does immunosuppression affect HZO?

Answer 22

It increases the risk of severe disease and complications, including prolonged viral shedding.

Question 23

What is the role of artificial tears in HZO management?

Answer 23

To relieve dryness and irritation in cases of keratitis or reduced tear production.

Question 24

How is uveitis associated with HZO treated?

Answer 24

Topical corticosteroids and cycloplegics, under the supervision of an ophthalmologist.

Question 25

Why is ophthalmology referral important in HZO?

Answer 25

To manage ocular complications such as keratitis, uveitis, and secondary glaucoma, which can threaten vision.