Vector: Lone Star tick (Amblyomma americanum). The adult female shows a white dot in the middle of its back. This is an aggressive tick. A patient often may not recall seeing an attached tick.
Distribution of tick: primarily in the Southeast. The range extends to:
(1) New York, Connecticut and Rhode Island
(2) most of Pennsylvania, Ohio, Indiana and Illinois
(3) eastern parts of Iowa, Nebraska and Kansas
Organism: Borrelia lonestari
Clinical features:
(1) expanding annular rash that is erythema migrans-like
(2) other clinical features suggestive of Lyme disease
(3) negative serologic tests for Borrelia burgdorferi
(4) no or low risk of late sequelae
Findings other than rash seen in 20-40% of patients:
(1) myalgias
(2) fever
(3) arthritis
(4) fatigue
Findings seen in < 6% of patients:
(1) severe headache
(2) night sweats
(3) stiff neck
(4) visual problems
(6) facial paralysis
A search of commercial laboratories in June, 2009 failed to find any that offered a diagnostic test.
The differential diagnosis includes other tick-borne infections.
