RESUMO
Lyme's disease (LD) is a multisystemic infection due to Borrelia Burgdorferi transmitted through the byte of a vector arthropod of the Ixodes genre. Until now we do not know exactly which is the geographical distribution in our setting, no case have been published in the Aragon Community. We present four patients diagnosed of Lyme's disease following clinical and serological criteria (IFI) according to the recommendations of the Spanish Group for the study of Lyme's disease. A patient with Chronic Migratory Erythema (ECM); two others in stage II--one with predominant dermal lesions and other with predominant neurological symptoms--and finally, a patient in stage III with polyarticular symptoms and with antecedent of having showed a lymphocytic meningoencephalitis.