Clinical characteristics and treatment outcome of early Lyme disease in patients with microbiologically confirmed erythema migrans.

BACKGROUND

Lyme disease has a wide spectrum of clinical manifestations. Diagnosis is usually based on the clinical and serologic picture rather than on microbiological confirmation.

OBJECTIVE

To examine the clinical presentation and treatment outcome of early Lyme disease in patients with microbiologically confirmed erythema migrans.

DESIGN

Observational cohort study.

SETTING

31 university-based or clinician-practice sites in 10 endemic states.

PARTICIPANTS

10 936 participants enrolled in a phase III trial of Lyme disease vaccine; 118 participants had erythema migrans in which Borrelia burgdorferi was detected by culture or polymerase chain reaction.

MEASUREMENTS: Clinical characteristics and treatment outcome were noted. Skin biopsies of erythema migrans were performed for culture and detection of B. burgdorferi by polymerase chain reaction; serologic responses were determined by Western blot.

RESULTS

The 118 patients with microbiologically confirmed erythema migrans presented a median of 3 days after symptom onset. Early erythema migrans commonly had homogeneous or central redness rather than a peripheral erythema with partial central clearing. The most common associated symptoms were low-grade fever, headache, neck stiffness, arthralgia, myalgia, or fatigue. By convalescence, 65% of patients had positive IgM or IgG antibody responses to B. burgdorferi. Most patients responded promptly to antibiotic treatment.

CONCLUSIONS

In major endemic areas in the United States, Lyme disease commonly presents as erythema migrans with homogeneous or central redness and nonspecific flu-like symptoms. Clinical outcome is excellent if antibiotic therapy is administered soon after symptom onset.