['The etiology of facial paresis (FP) often remains unresolved. Yet, a microbial association is frequently suspected.', 'To evaluate the infectious etiology of FP by using sensitive tests.', 'We studied the serum and cerebrospinal fluid of 42 patients diagnosed with idiopathic peripheral facial paresis using sensitive serological methods and nucleic acid detection and for reference, 42 patients with other neurological disorders (OND) matched for age, sex, season and geographical area.', 'Varicella zoster virus and Borrelia burgdorferi accounted for 56% of all associated agents in children with FP compared with 11% of OND (P=0.01). In adults, the respective numbers were 29 and 13%. Other treatable etiological agents, Chlamydia pneumoniae and Mycoplasma pneumoniae, accounted for 11% in children and 8% in adults and with the same prevalence between patients with FP and OND.'] Are varicella zoster and Borrelia burgdorferi the main agents associated with facial paresis , especially in children?