Table 1.

Demographic and baseline historical information

Characteristic	Value
Age (yr) [mean ± SD (range)]	47.7 ± 11.9 (32–73)
Male [n (%)]	4 (36)
Caucasian [n (%)]	11 (100)
Preexisting conditions [n (%)]	6 (54)
Osteoarthritis	4 (36)
Rheumatoid arthritis	1 (9)
Spondyloarthropathy	1 (9)
Distribution of arthritis [n (%)]
Monoarticular	6 (54)
Oligoarticular	5 (46)
Joint aspirated [n (%)]
Knee	9 (82)
Wrist	1 (9)
Elbow	1 (9)
Course of arthritis/joint effusion [n (%)]
Intermittent	11 (100)
Persistent	0 (0)
Time since onset of arthritis prior to consultation (days) [mean (range)]	1051 (122–2555)
History of erythema migrans rash [n (%)]	1 (9)
History of tick bite [n (%)]	1 (9)
Concurrent symptoms at time of consultation visit [n (%)]
Arthralgia	11 (100)
Subjective cognitive dysfunction	6 (54)
Fatigue	4 (36)
Myalgia	2 (18)
Prescribed antibiotic coursesa
Total no. of days of antibiotic therapy for seronegative patients [mean (range)]	72 (10–165)
Seronegative patients treated with oral antibioticsb [n (%)]	10 (100)
Duration (days) [mean (range)]	53 (10–108)
Patients treated with parenteral antibioticsc [n (%)]	5 (45)
Duration (days) [mean (range)]	38 (2–70)
Patients simultaneously receiving intravenous and oral antibiotics [n (%)]	5 (45)

^aOf the 10 seronegative patients.

^bDoxycycline, amoxicillin, clarithromycin, or azithromycin.

^cCeftriaxone.