The outcome of Lyme borreliosis in children.

Austria is an endemic area for Lyme borreliosis. The IgG seroprevalence of healthy blood donors as investigated by a DAKO flagellum-ELISA in Graz/Styria is 13%. In order to determine whether this high seroprevalence is caused by infection in childhood, 36 children aged 3 to 18 years (mean, 10.1 years) were followed up over 2 to 20 months (mean, 11.1 months) and reinvestigated for clinical symptoms and antibodies against B. burgdorferi by a commercial flagellum ELISA and a commercial B. garinii Western blot (WB). Twenty-seven children had erythema migrans (EM), one of them with reinfection, 5 had borrelia lymphocytoma (BL), 2 EM and BL, 1 acrodermatitis chronica atrophicans and 1 ACA/circumscribed scleroderma. Before treatment with either phenoxymethylpenicillin, amoxicillin, or minocyclin for 3-4 weeks, 64% of the patients were IgM and 44%, IgG seropositive. Clinically, all but 5 patients with EM recovered from Lyme borreliosis. Among these 5 patients--one of them with reinfection of EM--3 had mild arthralgia, 1 recurrent headache and 1 concentration disturbance. Only 2 children with arthralgia were IgM positive by ELISA and WB. One of 5 BL patients had a persistent swelling of the ear lobe although with a negative serology before and after several antibiotic treatments and at follow up. In 16 children serological investigations were performed after more than 12 months (range, 13-20 months). Eighteen percent of them had IgM antibodies by ELISA, 25% by WB, and 6% IgG antibodies by ELISA and 6% by WB. Although there was a decline of antibody response from 64% to 18% for IgM and from 44% to 6% for IgG as measured by ELISA, children remain seropositive for more than 1 year with or without clinical symptoms. The relevance of the association with clinical symptoms can be raised by combining several diagnostic methods. It is assumed that recurrent, often silent, infections might increase antibody titres. It should be noted that antibody titres also generally increase with the age of individuals.