Stupica D, et al. – Researchers compared the clinical course and treatment outcome of multiple erythema migrans (MEM, a manifestation of early Lyme borreliosis) and solitary EM to determine their potential differences. Findings revealed that post-treatment long-term outcome at 12 months was comparable irrespective of dissemination.

Methods

• They conducted this study from June 1, 2010, to October 31, 2015, at the University Medical Center Ljubljana, Slovenia, and analyzed data from June 1, 2017 to January 3, 2018.
• Of those evaluated with early Lyme borreliosis (n=778), 200 with MEM (median age: 47 years) and 403 with solitary EM (median age: 55 years) were included in the study.
• Control participants were patient-referred family members or friend of similar age (± 5 years) without a history of Lyme borreliosis.
• Outcomes were evaluated at 14 days and at 2, 6, and 12 months after enrollment.
• At each visit, patients and control participants were asked to complete a written questionnaire about their symptoms.
• Researchers compared nonspecific symptoms reported by patients and control participants without a history of Lyme borreliosis.
• They used the normal approximation with continuity correction to estimate the proportion of patients with incomplete response at 12 months after enrollment and the associated two-sided 95% confidence intervals for the difference between MEM and solitary EM.

Results

• Lyme borreliosis-associated constitutional symptoms at enrollment were more often observed among patients with MEM vs those with solitary EM (93 [46.5%]; 95% CI, 39.4-53.7 vs 96 [23.8%]; 95% CI, 19.7-28.3; P<0.001).
• In the MEM group vs the solitary EM group, a higher proportion of patients showed incomplete response during the initial 6 months after treatment (14 days: 62 of 193 [32.1%] vs 72 of 391 [18.4%]; P<0.001; 2 months: 38 of 193 [19.7%] vs 55 of 394 [14.0%]; P=0.28; 6 months: 29 of 182 [15.9%] vs 31 of 359 [8.6%]; P=0.02).
• However, comparable outcome was observed at the 12-month visit: 10 of 170 (5.9%) patients with MEM vs 20 of 308 (6.5%) patients with solitary EM showed incomplete response (-0.6; 95% CI, -5.5 to 4.3; P=0.95).
• Patients and control participants had similar frequency of nonspecific symptoms.