Makindo Medical Notes.com

Related Subjects: |Herpes Varicella-Zoster (Shingles) Infection |Chickenpox Varicella Infection |Varicella Cerebral Vasculopathy |Herpes Viruses |Herpes Zoster Ophthalmicus (HZO) Shingles

The virus also can affect the uveal tract and, in immunosuppressed patients, the retina and cause acute retinal necrosis. A vaccine is now available to prevent severe infection in older patients. Refer to ophthalmology. All patients with red eye or visual symptoms or Hutchinson's signs need an ophthalmology review

About

• Infection by Herpes Zoster

Aetiology

• Previous systemic infection (varicella, i.e. chickenpox) .
• The virus lies dormant in dorsal root ganglion and cranial nerve sensory ganglia
• Reactivation (stress, sunlight, menses) leads to zoster (shingles)
• Herpes zoster affects 20-30% of the population at some point
• Some will have infection involving the eye

Predisposing factors

• Age: 60+ years but can occur at any age
• Immune compromise: HIV/AIDS, medical immunosuppression

Clinical

• Pain and altered sensation of the forehead on the affected side
• General malaise, headache, fever, Lymphadenopathy
• Unilateral painful, red, vesicular rash on the forehead to vertex and upper eyelid, progressing to crusting after 2-3 weeks; resolution often involves scarring periorbital oedema (may close the eyelids and spread to opposite side)
• Rash at the side of the tip of the nose (Hutchinson's sign) indicates twice the usual incidence of ocular complications and involvement of uveal tract
• Neurological complications: cranial nerve palsies, optic neuritis, encephalitis
• Post-herpetic neuralgia: chronic and severe in about 7% of patients

Eye Involvement

• Mucopurulent conjunctivitis, associated with vesicles on the lid margin; usually resolves within 1 week
• Scleritis: less common; usually develops after 1 week
• Episcleritis: occurs in around one-third of cases
• Keratitis, reduced corneal sensation (neurotrophic keratitis)
• Anterior uveitis, Secondary glaucoma
• Retinitis, choroiditis, optic neuritis, optic atrophy

Differential

• HSV keratitis
• Cellulitis, contact dermatitis, atopic eczema, impetigo

Management

• Take expert advice on stopping immunosuppressants/steroids based on risks vs benefits. If admission is needed then isolate so that only those with immunity to chickenpox with antibodies are involved with care.
• Prevention: A vaccine is now available to prevent severe infection in older patients. This is given to adults age 70-79. See BNF reference
• Rest and general supportive measures (reassurance, support at home, good diet, plenty of fluids) and advise avoidance of contact with elderly or pregnant individuals, also babies and children not previously exposed to VZV (who are nonimmune) or immunodeficient patients.
• Pain relief: Aspirin, paracetamol or ibuprofen (check history for contraindications). Stronger analgesics (e.g. opiates) may be indicated (co-manage with GP)
• Early treatment with oral Aciclovir (within 72 hours after rash onset) reduces the percentage of eye disorders in ophthalmic zoster patients from 50% to 20-30%. This early treatment also lessens acute pain. Usually oral aciclovir (800 mg orally five times per day for 7 to 10 days).
• Topical steroids (e.g. Prednisolone acetate drops 1% four times daily and Atropine 1.0% once or twice daily) with antiviral as Immunosuppressive therapy for scleritis
• Botulinum toxin-induced ptosis or surgical tarsorrhaphy for neurotrophic corneal ulceration

References

• Ophthalmic herpes zoster
• Shingles NICE guidance November 2019