Thanks to A.Hill for today’s pearl:

19M presents with fever and rash on palms and soles x1 week.

Vitals: Temp 101 HR 105 BP 130/80 RR 12 O2 100%

What is the differential for rash on the palms and soles?

Disseminated gonococcus

Rocky mtn spotted fever

Hand, foot, and mouth disease

Secondary syphilis

Kawasaki disease

Toxic shock

Stevens-Johnson or TEN


On further history, the patient reports risky sexual behaviors and a painless chancre on his genitals 1 month ago.

What confirmatory test(s) can you order?

What is the treatment? What if he had no hx of chancre?


Screening Tests (low specificity) not appropriate for our high clinical suspicion

  • Venereal Disease Research Laboratory (VDRL)
  • Rapid Plasma Reagin (RPR)
  • Toludine Red Unheated Serum Test (TRUST)

Confirmatory tests (highly specific)

  • Fluorescent treponemal antibody absorption (FTA-ABS)
  • Microhemagglutination test for antibodies to Treponema pallidum (MHA-TP)
  • Treponema pallidum particle agglutination assay (TP-PA)
  • Treponema pallidum enzyme immunoassay (TP-EIA)
1) Early syphilis=less than one year of symptoms, either hx of  chancre or nonreactive syphilis serology within the past year.
One dose Penicillin G benzathine (2.4 million units)
2) Latent syphilis of unknown duration (+serology with no hx of chancre or nonreactive serology in last year)
Three doses of benzathine penicillin (2.4 million units IM) weekly
3) Latent tertiary syphilis=gummatous or cardiovascular syphilis with no CSF disease
Three doses of benzathine penicillin (2.4 million units IM) weekly
4) Neurosyphilis (diagnosed with CSF serologies) or Ocular syphilis (diagnosed by ophtho)

Intravenous penicillin G (3 to 4 million units IV Q 4h or 18 to 24 million units per day by continuous infusion for 10 to 14 days)