[Epidemics of laryngitis (8983 cases of laryngotracheitis and croup). I. Epidemiologic aspects].

They are retrospectively reviewed 893 croup cases, occurred in epidemic bout during September-October 1987, all of them were attended at our hospital's emergency room. Incidence was more frequent among males, aged 6 months to 3 years; the asked for medical attendance mostly by night. It was also investigated the stational distribution of 7,439 croup cases, occurred since June 1981 to December 1987. It was observed an epidemic bout pattern of biannual frequency, occurring in autumn and winter months, highest incidence observed in October.