Verma: Viral Exanthems Flashcards
A skin eruption occurring as a symptom of a general disease.
exanthem
Eruptive lesions on the mucous membranes.
enanthem
This is the most common viral exanthem; 1st disease; it was eliminated in the US in 2000
measles
How is measles acquired?
direct or airborne droplets
How long is the measles incubation period? How long is the infectious period?
7-18 days
1-2 days prior to prodrome, 4 days after rash onset
Is measles contagious?
YES, highly contagious!
What occurs during the prodrome phase in measles? When does the prodrome phase occur?
fever, coryza, conjunctivitis, cough (3 Cs); occurs 2-4 days before Koplik spots and 3-5 days before exanthem (rash)
How does the measles exanthem begin? Then what happens to the lesion?
around the ears as irregular macules; lesions spread to trunk in 24-48 hours, become more papular (purplish/red) and last 3-5 days
How can you diagnose measles?
Koplik spots, exanthem (rash) IgM in acute serum *most rapid detection PCR of throat swab looking for paramyxovirus Viral cultures Serial IgG
List some measles complications
otitis media
pneumonia
encephalitis
blindness due to Vit A deficiency
This is one of the first diseases to reappear when vaccine rates fall
measles
What should international travelers be given to avoid measles?
2 doses MMR
How to treat measles?
supportive treatment
Vit A in malnourished children
Live attenuated vaccine *prevention
Post-exposure prophylaxis with vaccine w/i 3 days or Ig within 6 days with vaccine 5-6 months later
Togavirus; “German measles;” 3rd disease
Rubella
How is rubella spread?
direct contact and droplets
How long is the incubation period in rubella? How long is the infectious period?
14-21 days; 5-7 days before rash onset, 3-5 days after rash
What does rubella present like clinically?
asymptomatic infection in up to 50% or low grade fever
children: rhinorrhea, cough, sore throat
adolescents/adults: malaise, sore throat, nausea, anorexia
enanthem
Forschheimer’s spots: petechiae on hard palate
What are Forschheimer’s spots?
petechiae on the hard palate
How does the rash in rubella start? What is one notable feature of the rash? How is it different from the measles rash?
starts on the face and then fades from face w/i 24 hours;
notable feature: appearance rapidly changes in 24 hours;
pink-red lesions in rubella, instead of purplish-red lesions in measles
What is the diagnostic testing for rubella?
IgM or IgG in serum
What are some complications of rubella?
arthralgias/arthritis in older pts
peripheral neuritis, encephalitis
congenital rubella syndrome: cataracts, microencephaly, deafness, cadiac defects, anemia, low platelets
When is a fetus at risk of becoming infected with rubella?
30-50% risk if mother is infected during the first 6 weeks of the pregnancy **early in first trimester
What causes fifth disease, or erythema infectiosum?
human parvovirus B19
How long is the incubation period for fifth disease? How long is this disease contagious?
4-14 days; only contagious in the first stage
Over 50% of fifth disease infections are (blank)
asymptomatic
How do you diagnose fifth disease?
detection of serum parvovirus B19-specific IgM antibody
What happens on day #1 in patients with fifth disease? What is unique about this stage of the disease?
slapped cheek appearance; it is contagious during this first stage
What happens on day #2 in patients with fifth disease (2nd stage)? What happens on day #6 (3rd stage)?
erythematous maculopapular eruption; reticular pattern of rash which lasts 9-11 days
What cells does the parvovirus B19 infect? So what are some complications?
erythrocytic precursors; can cause hemolysis and anemia, may need RBC transfusion, may cause hydrops fetalis (severe anemia leading to cardiac failure)
2nd syndrome ascribed to Parvovirus B19 Spring/Summer Young Adults Exanthem, LAD, fever, anorexia, arthralgias Self-limited over 7-14 days Viremia clears after rash
Papular purpuric glove and sock syndrome
What is Roseola infantum also called? What viruses cause this disease?
6th disease; Human herpes virus 6 and 7
What is unique about the infectious period of roseola infantum?
the virus is intermittently shed into the saliva throughout life, causing an asymptomatic persistent infection
How does roseola present clinically?
high fever for 3-4 days
followed by abrupt appearance of rash, which begins on the trunk and spreads to extremities
- *otherwise well-appearing child
- *febrile seizures may occur
How is herpes simplex transmitted?
through abraded skin or intact mucous membranes
What are the symptoms of herpes simplex infection?
painful, recurring vesicular eruptions that are worse primarily than they are when they recur;
fever, LAD, and malaise w primary infection;
prodromal tingling, burning or pain
Two ways in which varicella zoster (chicken pox) is spread?
respiratory droplets
vesicle fluid
Symptoms of the prodrome phase of chicken pox?
asymptomatic to fever, malaise, cough, coryza, sore throat
**coryza: inflammation of mucous membranes of the nose
One complication associated with chicken pox?
secondary bacterial infection
**occurs 5-10% of the time
What would you give an immunocompotent patient if they were exposed to varicella zoster?
varicella vaccine prophylaxis w/i 72hrs
Treatment for herpes viruses, including chicken pox?
acyclovir
What age are the majority of shingles patients? What is one complication with immunocompromised patients?
> 50yo; reactivation of the virus may occur multiple times
Describe the progression of small box
prodrome phase: chills, fever, backache, malaise
exanthem starts on face/forearms and spreads to trunk and legs last (centrifugal - from distal to core)
macular vesicles –> papular vesicles –> thick walled pustules
What drug WAS used for small pox?
**it has been eradicated globally
anti-viral cidofovir
Enteroviruses, like coxsackie A16 cause this disease…
hand-foot-and-mouth disease
What symptoms does hand-foot-and-mouth disease cause? Is it contagious?
highly contagious; low-grade fever, anorexia, malaise, sore mouth, rash
So what would be the difference b/w enantham and exanthem?
enantham is in the mucous membranes, while exanthem is in the skin
What virus causes herpangina? What is it?
Coxsackie A virus; painful mouth ulcers preceded by fever and sore throat
What does enterovirus D68 cause?
severe respiratory illness
pin pointed generalized rash
How does enterovirus D68 spread?
from person to person through coughs, sneezes, or contaminated surfaces
Pink macules and papules surrounded by white halos. Begins on trunk, spreads to neck and proximal extremities.
roseola infantum (exanthem subitum)
