Infectious Disease

Question 1

Infant with...
RDS
hepatomegaly
rash
swollen left wrist/limited ROM
thombocytopenia/anemia
hyperbilirubinemia/hemolysis

Answer 1

Treponema Pallidum 
(congenital syphilis) 
-rash: desqaumating (palms/soles)
-CXR: bronchopneumonia
-bone: metaphysical osteomyelitis (radiolucent distal radius, cupping of ulna)

Question 2

Describe the transmission pattern of congenital syphilis.

Answer 2

• risk of transmission increases as pregnancy advances
• untreated mom: 60-100% risk of transmission
• inc. in women w/substance use, no prenatal care

Question 3

How many infants with congenital syphilis are symptomatic at birth?

Answer 3

1/3

Question 4

What are the categories of testing for congenital syphilis?

Answer 4

1) non-treponemal
- RPR, VDRL
- detects IgM/IgG antibodies against cardiolipins
- if positive, dilution is performed (highest dilution with positivity, titer INCREASES with active disease)
2) treponemal
- FT-ABS

Question 5

Which type of syphilis testing remains positive for life?

Answer 5

-treponemal testing

Question 6

Can syphilis testing result in a false negative? If so, why?

Answer 6

• low antibody titers in early/late infection
• antibody titers are HIGH: prozone phenomenon with undiluted serum (high Ab titer can interfere with formation of cardiolipin lattice)
• 2% of results: often during pregnancy (late primary or secondary syphilis)
• dilute serum: reduces Ab concentration, agglutination can occur

Question 7

What is the primary mode of transmission of congenital syphilis? Risk of infection if untreated? early? late?

Answer 7

Transplacental route

• untreated primary/secondary: 60-100% risk
• early latent maternal infxn: 40% risk
• late latent maternal infxn: 8% risk

Question 8

How do most fetuses acquire intrauterine syphilis infection? Complications?

Answer 8

• hematogenous transmission
• > still birth (30-40%)
• > hydrops, IUGR, preterm birth

Question 9

Early (asx/symptomatic?) v. Late congenital syphilis timeline?

Answer 9

Early = <2 yrs of age
-2/3 asymptomatic, 1/3 symptomatic
Late = >2 yrs of age

Question 10

Which congenital infection may cause an unexplained large placenta?

Answer 10

syphilis

Question 11

Pneumonitis
Bullous eruptions
Rhinitis
HSM
hyperbili/hemolytic anemia, thrombocytopenia
leukopenia/leukocytosis
nephrotic syndrome
chorioretinitis/uveitis
osteochondritis
LAD
Erbs palsy/leptomeningitis

Answer 11

early congenital syphilis

osteo=wimberger sign!

Question 12

frontal bossing
saddle nose
high arched palate
short maxilla
perioral fissures
saber shin 
hydrocephalus
MR

Answer 12

late congenital syphilis

-saber shin: anterior bowing of tibia