A 6-year-old girl has a fever of 101F, malaise, and anorexia for two days. As the fever abates, a
maculopapular rash starts on her face and spreads downward to involve her entire body; it lasts
three days. On examination she has tenderness to palpation of the suboccipital and postauricular
areas. Which of the following is the most likely diagnosis?
- A) Rubeola
- B) German measles
- C) Mumps
- D) Roseola
- E) Fifth disease
0 voters
Rubella (German measles; three-day measles)
Presentation1
• Classically pediatric viral illness, with peak incidence age 5-9.
• Three-day prodrome of fever, malaise, and anorexia.
• As the fever abates, a maculopapular rash starts at the head and descends to cover the whole
body.
• Suboccipital and/or postauricular lymphadenopathy (exceedingly HY)
• Adults may present with arthritis
Vaccine
• Rubella is rare in the United States because of the Mumps-Measles-Rubella (MMR) liveattenuated vaccine.1
• First dose given at age 12-15 months; second dose given age 4-6 years.2
• MMR and varicella/zoster are the only live-attenuated vaccines approved for use in HIV
patients (CD4 must be >200 cells/mm3
).3
Congenital rubella1
• Disease occurs secondary to first-trimester in utero infection in non-immune mother.
• As mentioned above, pregnant adult female may present with arthritis.
• Neonatal deafness, meningoencephalitis, cataracts
• Patent ductus arteriosus (PDA) in neonate (exceedingly HY)
Rubeola (measles) High fever, cough, coryza, conjunctivitis (3Cs).4
• Koplik spots 2-3 days after symptoms begin and are described as punctate white spots on an
erythematous background on the buccal mucosa.5
• As the fever abates, a maculopapular rash starts at the head and descends to cover the whole
body (similar to rubella).4
Mumps6
• Classically presents as parotitis; orchitis and meningitis may also be seen (POM).
• Rash is not part of the classic disease presentation.
Roseola infantum (exanthem subitum; Sixth disease)7
• Caused by HHV6 (human herpes virus 6)
• High-grade fever (i.e., up to 104F) for 3-5 days.
• This is followed by a rapid defervescence of the fever with an accompanying maculopapular
rash.
• For the USMLE, just remember: “spiking fever followed by a rash.”
Fifth disease (erythema infectiosum; Fifth disease)8
• Characteristic facial rash described as a “slapped cheek” appearance
• By the time the rash appears, the virus is no longer infectious (i.e., cleared by the immune
system). For behavioral science USMLE questions, you can tell the worried parent that the child
will be okay.
• Can cause aplastic anemia (↓ RBCs + ↓ WBCs + ↓ platelets – i.e., all are decreased); more
common in children with RBC conditions associated with shortened lifespan, i.e., sickle cell.
• Associated with daycare centers.
• Can present as arthritis and lacy rash in adult.
Bottom line: These conditions are known as viral exanthems. They are all exceedingly HY
on the USMLE.