CSIM 1.17 - Viruses and Rashes Flashcards
Describe the basic features of maculopapular rashes?
Red
Possibly slightly raised
Can NOT diagnose on rash alone
Describe the basic features of vesicular rashes?
Fluid filled
More raised lesions (pustules)
Viral replication occurs WITHIN the rash lesions
Name five viruses that lead to maculopapular rashes?
Measles Rubella Parvovirus B19 HHV 6 HHV7
Name three viruses that lead to vesicular rashes?
HSV
Varicella-zoster virus
Pox viruses
Describe the basic features of measles, mumps and rubella viruses?
ALL single stranded RNA viruses ALL enveloped Measles and Mumps = Negative sense Rubella = Positive sense All spread via respiratory route
Which viral infection contains a statuary legal requirement to inform Public Health England?
Measles
What is the incubation period and generation time for measles?
I.P = 10-14 days G.T = 2-3 days before rash to 5 days after
What symptoms are commonly associated with measles?
Fever + (3c's) Cough Coryza Conjunctivitis Maculopapular rash
Which is the differentiating diagnostic sign in a measles presentation?
Koplik spots found on buccal mucosa
What type of vaccine is the MMR vaccination?
Live attenuated
What is the incubation period for rubella?
14-21 days
What type of rash is common with rubella?
Maculopapular rash
What are the complications that can arise with rubella infections?
Arthralgia (high in women)
Congenital rubella syndrome (before 12 weeks gestation)
Describe the basic features of parvovirus B19?
Single stranded DNA
Non enveloped
Respiratory route spread
What is the incubation period for parvovirus B19?
14-21 days
Infectious 7 days before the rash however with rash onset NO longer infectious
Describe the complications that may arise with infections of parvovirus B19?
Patients with haemolytic disorders may have an aplastic crisis - No reserves of RBCs
Foetal hydrops syndrome in pregnancy
Describe foetal hydrops and its treatment?
Parvovirus B19 destroys erythroid cell progenitors (foetal RBC have nucleus) leading to anaemia and heart tries to compensate leading to left ventricular failure - Fluid acumulates = pleural effusion and ascites
Treatment with foetal blood transfusion
Describe the clinical features of human herpes virus 6 + 7?
Maculopapular rash
Roseola infantum
Complications - encephalitis
Describe the basic features of enteroviruses and give three examples?
Single stranded RNA Non enveloped Maculopapular rash Polio Coxsackie Echo virus
