Exanthems Flashcards
Exanthems are?
external rashes
Enanthems are?
internal rashes
Forms of exanthems
Macular(flat),papular(raised),vesicular(cold sores),pustular(pus forming),or combination eg maculopapular.
Classic viral exanthems?
measles (rubeola, 1st disease), rubella (german measles, 3rd disease), parvovirus b19 (erythema infectiosum , 5th disease), HHV-6 & HHV-7 (roseola infantum, 6th disease)
Rubella characteristics ? (family, ss/ds/ RNA/DNA, shape, naked/enveloped, -/+ sense)
Togavirus(rubivirus), icosahedral capsid, enveloped, (+) ss RNA, linear.
How is rubella spread?
very contagious and spread by the respiratory route.
Rubella symptoms?
non specific macular rash observed on head,neck, and trunk. Low grade fever and sore throat.
Human herpesvirus 6 is a form of what?
beta herpes viruses . It is T cell tropic, but infects many cell types.
Human herpesvirus 6 is a form of what?
beta herpes viruses . It is T cell tropic, but infects many cell types.
Human herpes virus -6B diseases characteristics?
most common cause of febrile seizures (in children) , exanthem subitum (sudden rash), or roseola.
Major problem with HHV-6B? Treatment?
confusion with rubella. not antiviral treatment but can use herpesvirus treatment.
Where is HHV-6A predominantly found? HHV-6B?
6A is found in sub-Saharan Africa. 6B is found in Europe, Japan, and the US.
Latency for HHV-6?
about 90 % seropositivity at 2 yo. Shortly after primary infection , latent viral DNA can be detected in monocytes. After primary infection, cells contain life-long latent virus integrated into telomeres.
HHV-6 immunity and treatment?
No vaccine, treat with ganciclovir and foscarnet . ciHHV-6 individuals have little immunity against it due to tolerance.
