Incubation period: usually less than 10 days after the exposure
Typical findings:
(1) relapsing fever for weeks, up to 2 years
(2) skin rash which may involve the palms and soles
(3) chronic arthritis (oligoarthritis, polyarthritis, migratory) and/or arthralgias
(4) myalgias
(5) vomiting
Variable findings may include:
(1) endocarditis or pericarditis
(2) meningitis
(3) pneumonia
(4) visceral abscesses
(5) diarrhea
(6) pharyngitis
Laboratory findings include:
(1) leukocytosis
(2) false positive serologic tests for syphilis
If the history of a recent rat bite is known, then the differential diagnosis will include leptospirosis or other zoonosis.
If no connection is made with the rat bite, then the differential diagnosis may include:
(1) Rocky Mountain Spotted Fever (RMSF) or typhus
(2) Lyme disease
(3) meningococcemia
(4) brucellosis (especially if milk is ingested)
(5) rheumatoid arthritis or other rheumatic disorder
(6) viral infection
(7) enteric fever
(8) bacterial endocarditis
