Table 16.2.

Tick-borne illnesses clinical and laboratory findings

Disease	Incubation period	Clinical characteristics	Laboratory findings
RMSF R. Rickettsii	Symptoms appear 3–12 days after initial tick bite	Diffuse macular or papular rash starting on wrists and ankles (often palms/soles) spreading to arms, legs, trunk, associated with systemic symptoms such as fever, headache, myalgias, and malaise	Thrombocytopenia, increased hepatic transaminase levels, normal or increased white blood cell count with increased immature neutrophils, hyponatremia, increased serum urea nitrogen, creatinine, and bilirubin
Lyme disease	Symptoms appear 7–14 days after initial tick bite but may be as long as 30 days	Erythema migrans, solitary erythematous lesion, at site of tick bite followed weeks to months later by multiple erythema migrans, neurological, or cardiac sequelae, followed months to years later by arthritis	Mild thrombocytopenia, mild leukopenia, increased hepatic transaminase levels
Ehrlichiosis, E. Chaffeensis	Symptoms appear 1–2 weeks after tick bite, but shorter periods have been reported	Maculopapular rash, not as common as the RMSF rash and less often on palms and soles; leukopenia and thrombocytopenia	Leukopenia, thrombocytopenia, increased hepatic transaminase levels, hyponatremia, anemia
Babesiosis	Symptoms appear 1–6 weeks after tick bite	Fever, fatigue, weakness	Hemolysis of RBCs
Tick paralysis	Symptoms may not appear for several days after tick bite	Acute symmetric ascending paralysis eventually effecting the upper extremities and respiratory muscles; mental status not affected unless hypoxia from respiratory failure ensues	No laboratory abnormalities define tick paralysis