Shingles Flashcards
What is the epidemiology of shingles?
More common in the over 65s and immunocompromised
What is the aetiology and pathophysiology of shingles?
Caused by varicella zoster virus (VZV) reactivating (herpes virus 3); a double-stranded DNA virus
Lies dormant in the dorsal root ganglia of the spine, becomes reactivated and migrates down sensory nerves
Anyone who has previously had chickenpox may develop shingles
Can occur in childhood but more common in elderly
Once one episode has occurred, secondary reactivation is rare – 1%
What are some triggers for shingles?
Often affects people with poor immunity
Pressure on nerve root
Radiotherapy at the level of the nerve root
Spinal surgery
Infection
Injury (not necessarily to the spine)
Contact with someone with VZV
What is the time course of a shingles episode?
Symptoms subside as eruption disappears
Uncomplicated cases last 2-3wks in children/young adults and 3-4 in older patients
How does shingles present?
Pain – stabbing/burining, itching, paraesthesia; can be painless in children
Headache, fever, malaise; enlarge local lymph nodes
Rash – develops up to 3 days following pain unilateral (most frequently), thoracic/cervical/ophthalmic/lumbosacral areas most commonly affected, confined to a specific dermatome and not crossing the midline, red papules that blister/become pustular then crust over
What are some complications of shingles?
Bilateral/several dermatomal involvement
Deep blisters that destroy skin – scarring
Muscle weakness - facial nerve palsy = most common = Ramsay Hunt syndrome
Infection of internal organs including encephalitis, hepatitis etc – disseminated VZV
Post herpetic neuralgia
What is post herpetic neuralgia?
Persistence/recurrence of pain in same area more than 1 month after the onset of herpes
Increasingly common with age – 1/3 people
Particularly likely in facial
Continuous burning sensation, increased sensitivity, shooting pain, or itch (neuropathic pruritis)
May respond to topical anaesthetics/capsaicin, amitriptyline, gabapentin/pregabalin, BOTOX, acupuncture
How do you investigate shingles?
Usually clinical Dx
Viral PCR of lesion swabs
Can be confused with: Herpes simplex; Dermatitis herpetiformis; Impetigo; Contact dermatitis; Candidiasis; Drug reactions; Scabies; Insect bites
How do you manage shingles?
Paracetamol + rest
Keep rash clean/dry to reduce infection risk; PO ABx for any secondary bacterial infections
Wear loose fitting clothing; cool compress; no plasters
What antiviral treatment can be used for shingles?
Reduction of pain and duration if started within 1-3 days of
Acyclovir 800mg 5x day 7 days
i) Also valaciclovir and famciclovir
How do you manage the shingles infection risk?
Herpes zoster is infection to people who have not had chickenpox
i) Especially bad for pregnant women so avoid
Away from the ill/immunocompromised
Away from babies less than 1 month old (unless its yours)
Stay off school/work until the rash scabs – only infections whilst oozing fluid
You cant get shingles from someone with chickenpox but you can get chickenpox from someone with shingles if you haven’t had it before
What is the vaccination procedure for shingles?
Risks of complications are greater in elderly – NHS zoster vaccination available for 70< cuts risk of infection by 50%
In those that get it but are vaccinated – less severe and post hepatic neuralgia rarer
What is Ramsay hunt syndrome?
Rare peripheral facial neuropathy secondary to VZV reactivating in the geniculate ganglion of CN7 supplying facial nerve
5/100,000; F>M; more common with age
12% of all facial nerve palsies; 2nd most common cause of non-traumatic facial paralysis
How does Ramsay Hunt syndrome present?
General unwellness
Unilateral facial weakness – sometimes several days before blisters; painful blisters in the ipsilateral ear canal or mouth (though may be absent); loss of sensation/taste in the anterior 2/3rds of the tongue; dry eyes/mouth;
Occasional involvement of CN8 – dizziness, N+V; can spread to other CNs
How is Ramsay Hunt diagnosed?
Usually clinical Dx
Confirmation with VZV PCR assay using ear exudate useful for distinguishing zoster sine herpete (without blisters) from Bell’s palsy
