Name the Childhood Exanthems

What is measles caused by? 

What is it general structure? 

What are its major proteins?

1. measles virus, RNA SS -ve sense, enveloped

3. F - fusion on surface - allows fusion with cell membrane, responsible for giant cell (syncitia) formation

Hemagglutinin, Matrix, Nucleoprotein protects viral RNA

Phosphoprotein - RNA dependent RNA pol

How is measles transmitted? 

What is the incubation period? 

What are the general signs and sx? 

1. Resp droplets, most infectious during the late prodromal phase of the illness

2. 8-12 days, contagious 1-2 days before onset of to 4 days after apperance of rash

3. Fever - crescendo max at 5 to 6th day

Coryza - 24 hr after fever, sneezing, mucopurulent discharge Cough, Kaplik's spots - oral mucosa

Rash - appears 3-4 days after onset of illness, hairline, forehead spreads downward, feet by day 3

What are atypical and modified measles? 

Atypical - formulin inactivated mealses vaccine that didn't work given in the 60's get really bad case of measles 

Modified - passively immunzied by mom or IG

incubation is longer 14-20 and milder and shorter

What are the complications of measles? 

How do you dx? Tx? Px? 

Otitis media, pneumonia, acute encephalitis, subacute sclerosing panencephalitis - progressivce neuro degeneration

Dx - clinical, viral isolation, serology 

Tx - supportive, Vit A

Px - passive Ig, Measles vaccine (live)

Rubella (german measles) what is it? 

What is its general structure? 

How is it transmitted? 

caused by rubella virus, RNA SS +ve sense, 

2. spherical enveloped, E1 Hemagglutinin

3. Resp secretions

Caused by prenatal infection, serious damage to fetus, 

Risk is greater in earlier in pregnancy 

All germ layers affected

GR, Ophthalmic defects, Deafness, Cardiac defects, CNS retardation, hepatomegaly, hepatitis, thrombocytopenia, speenomegaly

Dx - viral isolation, serology - acute and convalescent 

Prevention - Active immunization Rubella vaccine

What is Varicella caused by? 

What is its structure adn characteristics?

How is it spread? 

1. Varicella-zoster virus HHV-3

2. DNA DS, enveloped

3. Droplets resp, most infectious druning late prodromal phase, contagious 3 days before rash until lesions dry

Clinical manifestations of chicken pox? 

Tx?

Prevention? 

Complications? 

1. Incubation period is 10-21 days, fever, Centripetal rash, macular - papular - vesicular - pustular - crusting

2. acyclovir

3. Varicella zoster IG, Live vaccine

4. Bacterial Superinfecion bullous varicella - cellulitis 

pneumonia, encephalitis, hemorrhagic varicella, death

What is Roseola caused by? 

What is its general structure? 

How is it transmitted? 

What is its clinical presentation? 

Complications?

1. HHV-6 DS DNA, enveloped

3. Resp salivary 

4. incubation period is 9-10 days, fever abrupt for 3 - 4 days, Exanthem when fever leaves, macules or maculopapules, trunk and out. 

5. Seizures, miningoencephalitis

What is Fifth disease caused by? 

What is its general structure? 

Transmission?

Clinical Sx?

1. Human parvovirus B19

2. non enveloped icosahedral SS DNA

3. Resp

4. 6-14 day incubation, mild or no system sx, Rash slapped cheeks, head to ass spread, Aplastic crisis, hemoglobinopathies, Intrauterine infection - non immune hydrops

What is Smallpox caused by? 

General structure? 

Clinical Sx? 

1. Poxvirus, DNA virus, DS linear, brick shaped, replicates in cytoplasm

3. 1-3 is infection spread to regional lymph node

4-14 viremia, spleen liver, reticuloendothelial system

Prodrone is after 7 -17 days and to the dermis - abrupt onset, HA/ backache, Fever, enanthema - mouth tongue oropharynx

Rash - eruption - papules - vesicles - pustules - crusts - desquamation