Viral Exanthems - Verma Flashcards
WHat is an exanthem?
skin eruption caused by a state of disease
what is an enanthem?
eruptive lesions on the mucous membranes
What are the six viral exanthems?
I. Measles (Rubeola) II. Scarlet Fever (Scarlatina) III. Rubella (German Measles) IV. Filatow-Dukes Disease V. Erythema Infectiosum VI. Roseola Infantum
What is 1st disease?
Measles
What virus causes measles?
paramyxovirus
What is the most common viral exanthem?
measles
T/F: measles has been eliminated from the US
true
What are the two methods of transmission of measles?
direct contact or airborne
What is the incubation period of measles?
7-18 days
How soon before rash onset with measles are you infective?
1-2 days prior to prodrome or 4 DAYS PRIOR TO RASH
What is the charactersitic enanthem of measle’s?
Koplick’s spots
How soon before the exanthem do Koplick’s spots appear?
2 days before
What are the 3 C’s associated with the measles prodrome?
coryza, conjunctivitis, and cough
The measles prodrome happens (blank) days prior to Koplick’s spots and (blank) days prior to the rash
2-4 days before spots, 3-5 days before rash
Where does the measles exanthem first show up on the body?
AROUND THE EARS as irregular macules
Where does the measles rash go after the face? How long does it take it to get there?
spreads to the trunk in 24-48 hours
HOw long does the measles rash last?
3-5 days
How does the measles rash change in appearance once it gets to the trunk?
becomes purple-ish red papular rash
Is the measles diagnosis clinical or lab based?
clinical; based on Koplick’s spots and exanthem
What is the most rapid lab test to detect measles?
IgM in acute infections
You can do a PCR of what sample type to Dx measles?
throat swab
Can you culture measles in house?
Nope, gotta send it to the state health dept.
When do you sue serial IgG tests to Dx measles?
in both the acute in convalescent sera
A vitamin A def. in measles can lead to what serious complication?
blindness
What is the most serious complication of measles?
subacute sclerosing panencephalitis
Besides blindness and SSPE, what are the other complications associated with measles?
otitis media and pneumonia and regular encephalitis
What is one of the first diseases to reappear when vaccination rates fall?
measles
How many doses of MMR should Intl travelers receive?
2 doses
What type of vaccine is MMR?
live attenuated
When are the two doses of MMR given?
at 12-15mos and at 4-6 years
What is the measles post-exposure prophylaxis?
Vaccine within three days or Ig within 6 days followed by vaccine 5-6 months later
What is 3rd disease?
Rubella aka german measles
What virus causes rubella?
togavirus
What are the two methods of transmission of rubella?
direct contact or airborne
what is the incubation period of rubella?
14-21 days
With regard to the rash, how long are you infectious before and after with rubella?
5-7 days before
3-5 days after
T/F: 50% of infections with rubella are asymptomatic
true
What is involved in the rubella prodrome?
low grade fever
What are the symptoms in children of rubella?
rhinorrhea, cough, and sore throat
What are the symptoms of rubella in adolescents?
malaise, sore throat, nausea
T/F: rubella presents with an enanthem
true
What is the name of the enanthem that presents with rubella?
Forschheimer’s spots; petechiae on the hard palate
Where on the body does the rubella rash begin?
on the face
How long does the rubella rash on the face last?
24 hours
T/F: the rubella rash can change appearance as quickly as within several hours
true
What color are the rubella rash lesions?
Pink-red
Measles are purple-red
What Ig do you use to Dx an acute infx of rubella and what Ig do you use to Dx a convalescent infx of rubella?
IgM for acute
IgG for convalescent
What is a complication of rubella that is seen in older pts?
arthralgias/arthritis
Congenital rubella syndrome is a risk if the mother is infected in the first (blank) weeks of the first trimester
six
Congenital rubella syndrome includes what effects to the fetus?
cataracts, microcephaly, deafness, cardiac defects, anemia, thrombocytopenia