Viral Skin Infections Flashcards
what are chicken pox and shingles due to
varicella zoster virus
how does shingles occur
reactivation of dormant VZV in dorsal root ganglion - is dermatomal
shingles vaccine
- type
- schedule
- side effects
- contraindications
- live attenuated
- given SC
- over 70 - catch up campaign
- chicken pox is a rare side effect
- as live contraindicated in IS, pregnancy and active infection
chicken pox symptoms
- fever
- itchy rash that starts on head/trunk then spreads
- initally macular then papular and then vesicular
- mild systemic upset
what are some 2y features of chickenpox
bacterial infection - due to scratching
pneumonitis
haemorrhagic
scarring encephalitis
haemorrhagic chickenpox
- Thrombocytopenia and purpura
- more common in IC etc
pneumonia as a complication of chicken pox
Chickenpox can spread to the lungs and cause pneumonia, more common in adults (smokers), pregnant people and those with weakened immune systems.
what is neonatal VSV
2y to chickenpox in mother in late pregnancy - may produce latency of VZV in the dorsal root ganglia of the foetus
what is the mortality of neonatal VSV like
higher than normal
how can you prevent neonatal VSV
varicella zoster immune globulin in susceptible women
who is shingles seen in
elderly and IC
shingles CF
tingling/pain that is greater with increasing age, followed by dermatomal rash
describe shingles pain
neuralgic - sharp and proximal along course of nerve
what is the complication that can occur if shingles lasts >4 weeks
post herpetic neuralgia - burning pain that lasts long after rash and blisters have disappeared
where does post herpetic neuralgia commonly affect
first branch of trigeminal nerve, but also V2 and V3
is scarring more common in shingles or chickenpox
chickenpox
herpes zoster ophthalmicus
zoster of CNVI (accounts for 20% of all shingles), affects the globe in 50%
waht is seen on the nose in herpes zoster ophthalmicus
- Hutchison’s sign: the nasociliary branch of CNV1 supplies the tip of the nose, this is a strong risk factor for ocular involvement
what is ramsay hunt syndrome caused by
complication of shingles - dormant VZV reactivates in the geniculate ganglion of CNVII
also known as herpes zoster oticus/geniculate
ramsay hunt syndrome CF
severe otalgia followed by VII and other cranial nerve palsy
zoster vesicles around ear and deep meatus (ear canal)
what nerve supplies the sensation of taste to the anterior 2/3 of tongue
CNVII
this is why taste is lost in ant 2/3 of tongue in Ramsay Hunt Syndrome
what is idiopathic CNVII palsy called
bells palsy
what may recurrent herpes infection cause
bells palsy - herpes inflames CNVII
in ramsay hunt syndrome what can irritation of CNVIII cause
deafness, vertigo and tinnitus
VSV and HSV therapy
acyclovir - antiviral
- oral for VZV, this reduces the incidence of post herpetic neuralgia
what is acyclovir
analogue of guanosine
what is the effect of acyclovir
doesnt eliminate virus - slows the growth and spread
presentation of erythema multiforme
multiple target lesions
what can erythema mulitforme be triggered by
hypersensitivity reaction triggered by
- Herpes simplex virus
- Mycoplasma pneumoniae bacterium
- Co-trixomazole treatment
erythema multiforme major
more severe form - has mucosal involvement
what is the name for pox virus
molluscum contagiosum
describe molluscum contagiosum
grouped, pearly white or pink, firm umbilicated papules
molluscum contagiosum treatment
liquid nitrogen
who is molluscum contagiosum common in
children