Shingles around the
eye, some notes
- PHN= postherpetic neuralgia
- ARN = acute retinal necrosis
- HZO = Herpes zoster ophthalmicus = shingles around the eye
Shingles around the eye, herpes zoster ophthalmicus (HZO) begins with a numbness around the eye in the area of the 5th ophthalmic nerve. The numbness starts to become a little worse, and then erythema (redness) of the skin in the same are develops. 1-2 days later, vesicles begin. These are 5mm crusting areas on the skin, and at this stage the diagnosis is obvious.
Over the next 4 weeks, various problems may develop. These include
- bacterial injection of the skin, needing antibiotics
- scarring of the skin
- pain around the eye
- later, even more pain around the eye (PHN: post-herpetic neuralgia)
- inflammation in the eye, such as uveitis, or cornea (keratitis)
- rarely, infection of the retina or brain
Early diagnosis helps
- Sometimes there is no rash, and the diagnosis is much harder to make.
- Treatment should be begun right away; early treatment prevents PHN.
- Treatment should certainly be begun when there is erythema or vesicles.
- Treatment is aimed at stopping viral reduplication primarily.
- The condition is much more common, and more serious, in the elderly/immunosuppressed.
- In theory, if there is numbness in this pattern around they eye, then treatment may be begun at this stage….but usually the diagnosis is not clear at this stage.
Spread of infection
- Generally the elderly/ immunosuppressed should keep away from patients with chickenpox (the same herpes- zoster virus)
- Shingles is also infective (causing chickenpox), so patients should be in their own room in hospital etc, and not be in contact with children or other immunosuppressed people.
- elderly and young
- if young...test for HIV
- more severe in older patients Ophthalmology
Many different problems may develop. They may develop shortly after the infection or over the next few weeks. These include
- eyelid and skin infection and later scarring
- Keratitis, a corneal infection, which usually settles with treatment (antivirals as above +/- steroid drops).
- Late keratitis suggests persistent activity.
- uveitis/iritis (inflammation in the front chamber of the eye), needing antivirals, steroid drops, drops to dilate the pupil, drops to lower the pressure
- glaucoma (high pressure in the eye)
- later, cataracts
- retinal probems...a little macular oedema
- much more severe retinal problems, such as infection needing high dose treatment (this is rare)
- optic nerve, eye movement, orbit, and other problems
- 40% hzo keratit :
Punctate, dendritic, or disciform keratits,
- (psuedodendrites that are mucous and can be wiped),
- always test for sensation
- Treatment is aimed at stopping viral reduplication primarily.
- If uveitis develops, this also needs treatment.
- Treat the pain of the acute episode & PHN.
- In the acute stage, there may be a skin infection also which needs antibiotics (often a staph infection).
- The antivirals: examples include acyclovir, famciclovir, valcyclovir. (Zovirax, Famvir, Valtrex). Birudin is a newer one daily drug
- Aciclovir is generally the cheapest but has to be given the most often; high dose aciclovir.
- See www.patient.co.uk https://shinglessupport.org.uk/
- The treatment is nearly 100% safe so there is virtually no danger of starting early. Reduce dose if renal function reduced, check U & Es especially in the elderly.
- People who are immunosuppressed or have a very severe attack need intravenous acyclovir (or equivalent) for 1-2 weeks or longer. Immunosuppressed usually need intravenous acilcoivir (or an equivalent
potent antiviral)...eg all leukaemia patients.
- Who is immunosuppressed? ...patients using systemic steroids, having treatment for blood disorders, or any severe illness.
- Treat till the vesicles stop coming, generally 7-10 days.
- Monitor renal function and reduce dose if renal function reduces
- Always start & continue if new vesicles are
appearing; if immunosuppressed, continue even weeks later.
- Ganciclovir can be used topically.
Systemic steroids may be needed. They used
to be used, then we were advised they were unnecessary, but now believe
the are sometimes necessary. Use if severe skin bullae proptosis, ophthalmoplegia,
optic neuritis, ARN.
Parts of the eye
- There is commonly inflammation in the anterior chamber, often starting about 2 weeks after the skin infection.
- The inflammation commonly becomes chronic.
- It is prevented or reduced in severity (almost certainly) by prompt anti-viral treatment. This inflammation is called uveitis or iritis. It may cause the pupil to stick to the lens, and may block the drainage angle causing glaucoma. Steroid drops are needed, and drops to dilate the pupil, as well as continuing the antivirals.
- At this stage no one knows how long the antivirals should be continued, but if the uveitis continues they my be best continued for sometime, perhaps at a slightly lower dose. If the inflammation continues, some experts long-term use of the anti-viral treatment.
We are learning that attacks of HZO may not be noticed at the beginning, in that is there is no obvious skin infection, and all that is noticed is the inflammation such as the uveitis. This type of infection is a problem in the sense that it is not clear when and how long antivirals are needed. The eye problem, usually uveitis, still needs the routine treatment (steroid and dilating +/- anti-pressure drops), but may need antivirals short or long-term.
Post herpetic neuralgia (PHN)
- At 12 months, 37% >60y; 50% >70y
- leading cause of chronic pain/suicide, severe distress
- reduced with early antiviral treatment
- treat the HZV pain early...this prevents PHN.
- use opioid analgesics early to prevent pain pathways development
- Detail https://shinglessupport.org.uk/.
- Treatment protocol.
What is post-herpetic neuralgia (PHN)?
An acute attack of shingles often causes pain. Pain usually ceases when the shingles rash clears up. It may continue after the shingles has resolved and it is then defined as PHN.
What are the characteristics of pain in PHN?
Pain may be either constant or intermittent and is typically burning, stabbing or itching in character and located in the same dermatome distribution as the acute rash. Allodynia refers to the precipitation of pain by a non-painful stimulus, such as touch or pressure. It is often a distressing feature of PHN. Sleep disturbance and clinical depression are not uncommon.
- Treatment during the acute phase, antivirals as above
- Simple analgesics such as paracetamol are unlikely to be effective on their own but may contribute to improved overall analgesia.
- Tricyclic antidepressants (TCAs) and/or anticonvulsants.
Pain relief begins when issue levels are established i.e. 2 to 3 weeks. Treatment depends on age, comorbidity and frailty, phase of illness,acute zoster or established PHN, predominant symptom (allodynia or pain)
- gabapentin or pregabalin
- capsaicin 0.075%
- 5% lidocaine plasters
- amitriptyline and nortriptyline
- strong opioids
- drug combinations
- chronic pain clinic advice:
These offer additional treatments for PHN which include other more specialised drugs (such as opioids, ketamine, cannabinoids, etc), peri-neural local anaesthetic injections, physiotherapy, TENS and psychological coping strategies.