INTRODUCTION
Wheezing is a common public health problem in preschool children, especially in children under one year old, causing frequent hospitalizations. 1, 2 Wheezing is one of the most common respiratory symptoms in childhood, and according to epidemiological studies, the frequency of wheezing is 25% in the first 3 years and 46% in the first 5 years. 2-5 Wheezing child is a heterogeneous situation with different phenotypes. Optimal treatment is required to reduce the frequency and severity of episodes in future period. Since the causes and pathogenesis of wheezing in children are very different, determining the wheezing phenotype and appropriate regulation of the treatment is the most important approach that determines the course of the disease. 5-7
The simplest clinical classification of wheezing: 2, 3, 5, 8 episodic viral wheezing (EVW) and multiple trigger wheezing (MTW). The most common phenotype is EVW. Episodic viral wheezing is characterized by the fact that the wheezing attack is triggered by a viral upper respiratory tract infection (URTI) and the patient is asymptomatic between the attacks. In this group, respiratory tract infection is usually evaluated clinically, not by microbiological diagnosis. Among the most causative agents are rhinovirus, respiratory syncytial virus (RSV), coronavirus, human metapneumovirus, parainfluenza virus and adenoviruses. 2, 5 Although episodic viral wheezing usually regresses around the age of 6, some patients may continue at school age or turn into the MTW phenotype.8 In the second type of MTW, attacks can be triggered not only by viral respiratory infections but also by allergens, air pollutants or exercise. 8
Differentiation of temporary or persistent wheezing in early childhood is an important problem. Since wheezing attacks in the early period of life may be the first sign of asthma that may develop later, determining the risk factors for the development of asthma in infancy is important in terms of prognosis. However, there is no biochemical or genetic marker that predicts the development of asthma in small children. Asthma predictive index (API) has been developed to predict who will develop asthma among children under five years age with recurrent wheezing.9, 10 After the first definition of this index, the criteria were reviewed and the modified asthma predictive index (mAPI) was defined. 10 If mAPI is negative in the first 3 years, it is predicted that very probably there will be no asthma at 6 years of age, whereas if mAPI is positive in the first 3 years, it is predicted that the possibility of developing asthma in the future is higher. 11
Leukotriene receptor antagonists (LTRAs) block cysteinyl leukotriene receptors, which are known to be very important in wheezing pathophysiology. Leukotrienes are proinflammatory mediators released mainly by mast cells, triggering bronchoconstriction, eosinophil chemotaxis and mucus secretion in the respiratory tract, causing increased vascular permeability. After all, LTRA’s have significant anti-inflammatory and bronchoprotective effects. 4, 7, 12 However, the results of studies investigating the effect of the use of LTRAs as maintenance or intermittent therapy on the frequency and severity of attacks in children with EVW are contradictory.13-15 The aim of this study is to evaluate the effectiveness of montelukast in pediatric patients with episodic wheezing and API negative.
MATERIAL AND METHODS
This is a single center study. Patients who applied with recurrent wheezing attacks to the pediatric allergy outpatient clinic at Mersin City Hospital between 01/07/2019 - 01/08/2020 were included in the study. In patients with recurrent wheezing between the ages of 0-6, physical examinations were performed and eosinophil, total IgE, food mix sps IgE (milk, egg, soy wheat, nuts, fish), phadiotop (inhalant allergen sps IgE), skin prick tests were performed and the results were recorded in their files. The skin prick test was conducted with dermatophagoides pteronisinus, dermatophagoides farinae, alternaria, grain pollen, grass pollen, weed pollen, cat dog epithelium.
Episodic viral wheezing was evaluated as wheezing that develops following a URTI and is characterized by episodes without complaints between wheezing episodes. Upper respiratory tract infection was defined as the persistence of at least 2 of the following 5 symptoms: sneezing, coughing, nasal congestion, runny nose or fever (38.0°C) for 2 consecutive days.
The mAPI of all patients was evaluated. According to this index, at children who had four or more wheezing episodes, having 1 major or 2 minor criteria was considered positive.
Modified asthma predictive index:
Major criteria: 1. Doctor-diagnosed asthma in mother or father 2. Doctor-diagnosed atopic dermatitis 3. Sensitivity to at least one aeroallergen and Minor criteria: 1. Food allergy 2. Wheezing other than URTI 3. It was evaluated as eosinophilia (≥4%) in peripheral blood (Table 1). 16
Table 1. mAPI