Persistent Wheezing in Children

Abstract

Infants and very young children frequently experience wheezing. One third of school age children manifest recurrent wheezing during the first 5 years of life [1]. Wheezing is a common health problem and either transient or persistent, it causes significant morbidity, poor quality of life, frequent utilization of the health care system and high economic costs [1, 2].Wheezing has a broad age specific differential diagnosis. Asthma is the most prevalent diagnosis in all age groups and as it is not clearly documented in preschool ages, there have been attempts to classify preschool wheezing into different phenotypes to aid diagnosis, follow-up, and treatment. Our level of knowledge on phenotypes and their prognosis has strongly improved especially after the availability of the advanced age results of birth cohorts. The earliest classification scheme was proposed by Martinez in the Tucson Children’s Respiratory Study [3]. This scheme allowed us to recognize four phenotypes, as follows: never wheezed, early transient wheezers, persistent wheezers, and late-onset wheezers. Later schemes divided the persistent wheezers into those with and without allergy, with invariable involvement of immunoglobulin E [4, 5]. More practical approach was proposed by the European Respiratory Society Task Force to use the terms episodic wheezing to describe children who wheeze intermittently and are well between episodes, and multiple trigger wheezing for children who wheeze both during and outside discrete episodes [2]. Multiple trigger wheezing has been suggested that it may be an early indication of later allergic asthma and may be more likely to respond asthma treatment than episodic wheezing. In order to simplify etiologies in childhood wheezing, it is preferred to classify wheezing as acute and chronic (recurrent and persistent) wheezing and causes of chronic wheezing are outlined in Table 30.1 [6].