Viral infections of the skin Flashcards
Which virus causes chicken pox (varicella) and shingles?
Varicella (herpes) zoster
What kind of lesions are characteristic of chicken pox?
Macules to papules to vesicles to scabs (itchy)
How are the lesions in chicken pox typically distributed?
Usually centripetal (tend to be located on trunk)
Name four possible complications of varicella.
Bacterial infection Pneumonitis Haemorrhagic rash (purpura) Scarring Encephalitis
What are two severity predictors in chicken pox?
Extremes of age Impaired cell-mediated immunity
Which subset of patients tend to be affected by the rare complication of varicella pneumonia?
Teens, adults
How is neonatal varicella caused? How can this be prevented?
Infection of mother in late pregancy VZ immune globulin in susceptible women
How does shingles manifest?
Lesions in a particular dermatome
In what circumstances could opthalmic zoster occur in children?
Immunocompromised; if they had varicella in utero
What is Ramsay-Hunt syndrome? What are the possible symptoms and complications?
Reactivation in the facial nerve Vesicles and pain in the auditory canal/throat Facial palsy Irritate the 8th (vestibulocochlear) nerve causing deafness, tinnitus, vertigo
What kind of vaccine is used for varicella? When is this used in the UK?
Live attenuated Not routinely used in children, can be used in eldery to reduce impact of shingles and post-herpetic neuralgia
How does herpes simplex virus infection usually manifest in children?
Primary gingivostomatitis
What name is given to the recurrence of HSV, and what are the possible complications of this?
Cold sore Herpetic whitlow Eczema herpeticum (can be life threatening)
Which serotype of HSV is mainly responsible for oral lesions?
HSV-1
If a patient with herpes began to display signs/symptoms such as fever, fit, odd behaviour, hemiparesis and dysphasia, which diagnosis would be suspected?
Herpetic encephalitis
How does aciclovir work?
Guanosine analogue, incorporated into DNA
How can viral diagnoses be confirmed?
Viral swab (red-top vacutainer) Antibody tests (where infection site is inaccessible or as adjunct to viral swab)
Which virus is responsible for warts?
Human papillomavirus
Which serotypes of HPV are responsible for: a) warts b) genital warts c) cervical cancer
a) 1-4 b) 6 & 11 c) 16 & 18
Which serotypes of HPV does the Gardasil vaccine give protection against?
6, 16 & 18
Which disease does this picture show? How are these lesions described?
Molloscum contagiosum
Fleshy, firm, unbilicated, pearly nodules
“Target lesions” are the characteristic feature of which skin condition? What is it caused by?
Erythema multiforme
Many triggers- drug reactions, herpes simplex, mycoplasma pneumonia
What is herpangina and what are the causative organisms?
Blistering rash at back of mouth
Enteroviruses
Which viruses cause hand foot and mouth?
Enteroviruses, particularly Coxsackie virus
What are the symptoms of hand foot and mouth?
Flu-like illness, vesicular rash, mouth ulcers
What name is given to parvovirus B19 infection? (when it affects the skin)
Erythema infectiosum (slapped cheek disease)
What are the features of parvovirus B19 infection?
Facial rash which disappears after around 2-4 days, followed by development of rash on the extremities, mainly the extensor surfaces
May also cause arthritis- especially in wrists, and more promiment in adults
What are the possible complications of parvovirus infection?
Spontaneous abortion (preceded by foetal hydrops)
Aplastic crisis (seen in patients with reduced red cell life span)
Chronic anaemia
How is a diagnosis of parvovirus confirmed?
Parvovirus IgM
Which virus is associated with sheep farmers?
Orf
What is the causative organism in syphilis?
Treponema pallidum
How does syphilis manifest primarily, secondary and tertiary?
Painless ulcers at site of entry
Widespread erythema (esp. on palms and soles)
CNS, cardiovascular complications
