- Treponema pallidum (Syphilis)
- Dx: Darkfield microscopy; Screen w/ RPR/VDRL, Confirm w/ FTA-ABS.
- Primary: Painless chancre.
- Secondary: Rash on palms/soles, condylomata lata.
- Tertiary: Gummas, aortitis, Argyll Robertson pupil.
- Tx: Penicillin G. Watch for Jarisch-Herxheimer reaction.
- Borrelia burgdorferi (Lyme Disease)
- Vector: Ixodes tick.
- Stage 1: Erythema migrans (bull’s-eye rash).
- Stage 2: Bilateral facial nerve (CN VII) palsy, AV block.
- Stage 3: Migratory monoarthritis (esp. knee).
- Tx: Doxycycline. Use Ceftriaxone for severe/late disease.
- Leptospira interrogans (Leptospirosis)
- Source: Water contaminated with animal urine.
- Sx: Flu-like, severe myalgias (calves), conjunctival suffusion (red eyes, no exudate).
- Weil’s Disease: Severe form with jaundice, renal failure, and hemorrhage.
- Tx: Doxycycline or Penicillin G.