Childhood exanthematous diseases of presumable viral etiology have an important incidence in primary care, although the majorities are banal and self-limited diseases. Clinical characteristics supported the suspicion diagnosis, which was consistent with the observed epidemiological description and expected presentations of each disease. Although serological analysis could diminish the uncertainly on notification and control of diseases submited to especial programs of vaccination and eradication, they would not improve substantially the diagnosis and treatment of these patients.