Asthma diagnosis in infants and preschool children: a systematic review of clinical guidelines

Abstract Background and aim The definition and diagnosis of asthma are the subject of controversy that is particularly intense in the case of individuals in the first years of life, due to reasons such as the difficulty of performing objective pulmonary function tests or the high frequency with which the symptoms subside in the course of childhood. Since there is no consensus regarding the diagnosis of asthma in preschool children, a systematic review has been carried out. Materials and methods A systematic search was made of the clinical guidelines published in the last 10 years and containing information referred to the concept or diagnosis of asthma in childhood – including the first years of life (infants and preschool children). A series of key questions were established, and each selected guide was analyzed in search of answers to those questions. The review protocol was registered in the international prospective register of systematic reviews (PROSPERO), with registration number CRD42017074872. Results Twenty-one clinical guidelines were selected: 10 general guides (children and adults), eight pediatric guides and three guides focusing on preschool children. The immense majority accepted that asthma can be diagnosed from the first years of life, without requiring pulmonary function tests or other complementary techniques. The response to treatment and the exclusion of other alternative diagnoses are key elements for establishing the diagnosis. Only one of the guides denied the possibility of diagnosing asthma in preschool children. Conclusions There is generalized although not unanimous agreement that asthma can be diagnosed in preschool children.