Respiratory Disorders in Children Dr Varsha Atul Shah
Respiratory disorders are important as They account for 50% of consultations with general practitioners for acute illness in young children and one-third of consultations in older children Respiratory illness leads to 20-35% of acute paediatric admissions to hospital They are the fifth most common cause of death in children ages between one and 14 years in the UK Asthma is the most common chronic illness of childhood in the UK and the most frequent single cause for emergency hospital admission Cystic fibrosis is the most common lethal inherited disorder in Caucasians
Respiratory infections most frequent infections of childhood. The pre-school child has on average 6-8 respiratory infections a year. Most are mild, self-limiting illness but some, such as bronchiolitis or epiglottitis, are potentially life-threatening
Pathogens Viruses: cause 80-90% of childhood respiratory infections. The most important are the respiratory syncycial virus (RSV), rhinoviruses, parainfluenza, influenza and adenovirus. An individual virus can cause several different patterns of illness, e.g. RSV can cause bronchiolitis, croup, pneumonia or a common cold. The important bacterial respiratory pathogens are Streptococcus pneumoniae and other streptococci, Haemophilus influenzae, Bordetella pertussis which cause whooping cough, and mycoplasma pneumoniae. Mycobacterium tuberculosis remains an important pathogen. Some pathogens cause predictable epidemics, such as RSV bronchiolitis every winter, whereas others, e.g. pneumococcus, show little seasonal variation.
Host and environmental factors Poor socio-economic status (such as overcrowded, damp housing and poor nutrition) Larger family size Maternal smoking Boys more than girls Prematurity-especially infants who have required artificial ventilation Congenital abnormalities of the heart or lungs Rarely, immune deficiency, either congenital, e.g.agmmaglobulinaemia, or acquired, e.g. malignant disease or HIV infection.
The child’s age The child’s age influences the prevalence and severity of infections. It is in infancy that serious respiratory illness requiring hospital admission is the most common and the risk of death is great. There is an increased frequency of infections when the child or older siblings start nursery or school. Repeated upper respiratory tract infections are rarely an indication of underlying disease
Upper respiratory tract infection (URTI) 80% of respiratory infections involve only the nose, throat, ears and sinuses The term URTI embraces a number of different conditions: common cold (coryza) sore throat (pharyngitis, including tonsillitis) acute otitis media sinusitis
Clinical PresentationThe most common presentation is a child with a combination of a painful throat, fever, nasal blockage and discharge and earache. Cough is troublesome in many cases
URTIs may cause Difficulty in feeding in infants as their noses are blocked and this obstructs breathing Febrile convulsions Precipitation of acute asthma In infants, hospital admission may be required exclude a more serious infection
Brochiolitis Brochiolitis is the most common serious respiratory infection of infancy. Two to three per cent of all infants are admitted to hospital with the disease each year during annual winter epidemics. Ninety per cent are aged 1-9 months brochiolitis is rare after one year old. Respiratory syncitial virus (RSV) is the pathogen in 75-80% cases
Clinical features Coryzal symptoms precede a dry cough and increasing breathlessness. Wheezing is often but not always present. Feeding difficulties associated with increasing dyspnoea are often the reason for admission to hospital. Recurrent apnoea is a serious complication in infants in the first few months of life. Infants born prematurely who develop bronchopulmonary dysplasia and infants with congenital heart disease are more severely affected. The finding on examination are characteristic: Sharp, dry cough Tachypnoea Subcostal and intercostals recession Hyperinflation of the chest
Investigations RSV can be identified rapidly using a fluorescent antibody test on nasopharyngeal secretions. The chest X-ray shows hyperinflation of the lungs due to small airways obstruction and air trapping. Blood gas analysis, which is required in only the most severe cases, shows lowered arterial oxygen and raised CO2 tension
Management Is supportive. Humidified oxygen is delivered into a head-box, the concentration required is ascertained using a pulse oximeter. The child is monitored for apnoea. Mist, antibiotics and steroids are not helpful. Nebulised bronchodialators do not reduce the severity or duration of the illness. The antiviral drug ribavirin only marginally shortens viral excretion and clinical symptoms, and should be considered only for infants with underlying cardiopulmonary disorders or immunodeficiency. Fluids may need to be given by nasogastric tube or intravenously. Mechanical ventilation is required in about 2% of infants admitted to hospital
Prognosis Most infants recover from he acute infection within two weeks. However, as many as half will have recurrent episodes of cough and wheeze over the next 3-5 years. Rarely, the illness is very severe and results in permanent damage o the airway
Pneumonia A wide range of pathogens cause pneumonia in childhood and different organisms affect different age groups
In newborns The newborns is infected by organisms from the mother’s genital tract. The most common is the Group B β haemolytic streptococcus. Other pathogens are E.coli and other Gram- negative bacilli. Chlamydia trachomatis is an unusual but important pathogen.
In infancy In infancy, respiratory viruses, particularly RSV, are the most frequent cause but bacterial infection from Streptococcus pneumoniae and Haemophilus influenzae are also important. Staphylococcus aureus is uncommon but causes severe infection
Older Children As children become older, viruses become less frequent pathogens and bacterial infection more prominent. Mycoplasma pneumoniae is a common cause of pneumonia in school age children. Tuberculosis should be considered at all ages
Clinical Features Fever, cough breathlessness and lethargy following an upper respiratory tract infection are the usual presenting symptoms. Breathing is rapid, shallow and gives the impression that the child is afraid to breathe deeply. Pleuritic chest pain, neck stiffness and abdominal pain may be present if there is pleural inflammation.
Clinical Features Classical signs of consolidation with impaired percussion, decreased breath sound and brochial breathing are often absent, particularly in infants The chest X-ray may slow lobar consolidation, patchy bronchopneumonia or, less commonly, cavitation of the lung. Pleural effusions are quite common, particularly in bacterial pneumonia. Blood cultures, nasopharyngeal aspirates of viral isolation and a full blood count also be performed in children needing hospitalisation.
Management It is not possible to differentiate reliably between bacterial or viral infection on clinical or radiological grounds, so all children diagnosed as have pneumonia should receive antibiotics. As it is unlikely for the pathogen to be known when treatment is started, the choice of antibiotic is determined by the child’s age, severity of illness and appearance of the chest X-ray. If intravenous therapy is required, activity against pneumococci, H. influenzae and Staph. aures can be achieved with a second-generation cephalosporin.
Management Oral antibiotics are given for less severe infections. If M.pneumoniae or Chlamydia trachomatis pneumonia is suspected, erythromycin is given. Physiotherpy, an adequate fluid intake and oxygen in severe pneumonia may be required. If a child has recurrent or persistent pneumonia, investigations to exclude an underlying condition such as cystic fibrosis or immunodeficiency is indicated