The importance of the size of erythema migrans (EM) for diagnosis of Lyme borreliosis in Slovenian children

• Main Authors: Maja Arnež, Eva Ružić-Sabljić
• Format: Article
• Language: English
• Published: Slovenian Medical Association 2012-06-01
• Series: Zdravniški Vestnik
• Online Access: http://vestnik.szd.si/index.php/ZdravVest/article/view/583

Background: To see how often the largest diameter of EM was less than 5 cm and to compare clinical features and course of the disease in patients with EM < 5 cm and EM ≥ 5 cm. Methods: 650 patients < 15 years of age referred to our institution from 1996 to 2004 with solitary EM were included in this prospective study. Clinical data were collected by questionnaire. Blood was taken and antibiotics were prescribed. Course of the disease was evaluated by follow-up for at least one year. Results: 81 patients had EM < 5 cm. At presentation, patients with EM < 5 cm had shorter incubation period, shorter duration of EM, less frequently ring-like EM and more frequently EM on the trunk and limbs. Patients with EM ≥ 5 cm more frequently presented with fatigue and regional lymphadenopathy. Laboratory findings were comparable. In both groups of patients Borrelia burgdorferi sensu lato bacteremia was found in 7.6 %. Post-treatment course of the disease was also comparable between the two groups. Conclusions: In 12.5 % of patients aged < 15 years with solitary EM the largest diameter of skin lesion was less than 5 cm. Despite the differences in clinical features at presentation, the course of the disease in patients with EM < 5 cm and EM ≥ 5 cm was comparable. Thus, from clinical point of view it is not wise to wait until the skin lesion enlarges to 5 cm in diameter, but start appropriate treatment at once to avoid dissemination of borrelial infection.