Prevalence and clinical characteristics of wheezing in children in the first year of life, living in Cuiabá, Mato Grosso, Brazil

To evaluate the prevalence and the clinical characteristics of wheezing in 12-15 months old infants in the city of Cuiabá, Mato Grosso State, Midwest Brazil.Parents and/or guardians of infants were interviewed and completed a written standardized questionnaire of the "Estudio Internacional de Sibilancia en Lactantes" (EISL) - phase 3 at primary health care clinics at the same day of children vaccination or at home, from August 2009 to November 2010.1,060 parents and/or guardians completed the questionnaire, and 514 (48.5%) infants were male. Among the studied infants, 294 (27.7%) had at least one episode of wheezing during the first year of life, beginning at 5.8±3.0 months of age, with a predominance of male patients. The prevalence of occasional wheezing (<3 episodes of wheezing) was 15.0% and recurrent wheezing (≥ 3 episodes) was 12.7%. Among the infants with recurrent wheezing, the use of inhaled β2-agonist, oral corticosteroid, leukotriene receptor antagonist, as well as night symptoms, respiratory distress and hospitalization due to severe episodes were significantly more frequent. Physician-diagnosed asthma was observed in 28 (9.5%) of the wheezing infants. Among the wheezing infants, 80 (27.7%) were diagnosed with pneumonia, of whom 33 (11.2%) required hospitalization, neverthless no differences between occasional and recurrent wheezing infants were found.The prevalence of recurrent wheezing and physician-diagnosed asthma in infants were lower compared with those found in other Brazilian studies Recurrent wheezing had early onset and high morbity.