Internal Medicine

0521779407-13 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:15

928 Lyme Disease

also reported; systemic symptoms (fatigue, myalgias, joint pain,

fever) also common

■Late disease-occurs months to years after initial exposure; most com-

mon manifestation is mono or oligoarthritis of large weight-bearing

joints, usually the knees; much less common is encephalopathy

(with sleep disturbances, memory and concentration difficulties)

and peripheral neuropathy (paresthesias and radicular pain)

■Congenital transmission of disease has not been documented

tests

■Serologic tests often negative in early disease and diagnosis made

clinically

■Later stages of disease almost always associated with positive sero-

logic tests; two stage antibody testing required: screening test

is either by indirect immunofluorescence (IFA) or enzyme-linked

immunosorbent assay (ELISA); all positive screening tests must be

confirmed by Western blot

■IgM antibody appears 2–4 weeks after erythema migrans, peaks at

6–8 weeks and declines to low levels by 6 months; IgG appears 6–8

weeks after infection, peaks at 4–6 months and remains positive at

low levels indefinitely

■Lyme urinary antigen test (LUAT) – not standardized and should NOT

be used to make diagnosis

■Neuroborelliosis – associated with abnormal cerebrospinal fluid

(pleocytosis, elevated protein or low glucose) and localized antibody

production (higher titers in cerebrospinal fluid than serum)

■Peripheral neuropathy associated with abnormal nerve conduction

studies

■Serologic tests plagued by lack of sensitivity and specificity, inter and

intralaboratory reproducibility and absence of national standard;

thus, serologic tests must be interpreted in context of clinical pre-

sentation and should only be ordered in patients with high likeli-

hood of disease, not in those with nonspecific symptoms of fatigue

or malaise

■Culture of organism not routinely done; PCR for organism not yet

standardized

differential diagnosis

■Local reaction to tick bite, urticaria, cellulitis can be confused with

erythema migrans; infectious or inflammatory arthritis; viral or

syphilitic meningitis