PERSONAL PRACTICE Paediatric pneumonia: a guide to diagnosis, investigation and treatment Pneumonia has a marked seasonal pattern, with a much higher prevalence throughout the winter due to the preponderance of infections such as respiratory syncytial virus (RSV), influenza and pneumococcus.1 With so many children affected, pneumonia presents a significant risk to child health and a burden on healthcare resources. With a wide range of presenting symptoms and potential complications, pneumonia poses a challenge for paediatricians. This article aims to guide physicians in the management, diagnosis and follow up of children with suspected pneumonia, as well as discuss future developments in this field. Ellen Crame Michael D Shields Patrick McCrossan What is pneumonia? Currently, no single definition of pneumonia exists that is universally accepted. Pneumonia is essentially an infection in the lower respiratory tract (bronchi to alveoli) in which the inflammatory process leads to accumulation of fluid in the airspaces which interferes with gas exchange, leading to the typical symptoms of tachypnoea, increased work of breathing, hypoxia and cough. Traditional pathological studies reported that there are four pathological stages of pneumonia: 1. Congestion: Over the first 24 hours there is alveolar oedema and vascular congestion. 2. Red hepatisation: In days 2e4, exudate, containing red blood cells, neutrophils and fibrin fill the airspaces making them more solid. 3. Grey hepatisation: In days 5e7, the red cells in the exudate are beginning to break down. 4. Resolution: From day 8 up to 3 weeks the exudate is broken down by enzymes, digested by macrophages or coughed up as sputum. Pneumonia can be classified based on the radiographic appearance although this does not necessarily correlate with severity or aetiology of the disease. Bronchopneumonia (see Figure 1) appears as bilateral multifocal consolidative patches. This can progress to lobar pneumonia (see Figure 2) where there is a large and continuous consolidation of an entire lobe within the lung. Round pneumonia (see Figure 3) is a phenomenon of children whereby the radiograph depicts a round, wellcircumscribed opacity most commonly in the lower lobes. Round pneumonia is thought to be due to underdevelopment of the pores of Kohn and canals of Lambert, which in adults, allows dissemination of infection throughout a lobe. Abstract Community-acquired pneumonia remains the leading cause of death in children under 5 years of age throughout the world. Community acquired pneumonia can include bacterial, viral and fungal causes but it is very difﬁcult to clinically differentiate between them. Whilst viral pathogens have been identiﬁed as the most common aetiology, bacterial infections are considered the more likely to cause severe disease. It is important that the clinician has the ability to safely differentiate between those that may require further treatment or admission to hospital and those that can be managed at home. With a wide range of presenting symptoms and potential complications, pneumonia poses a challenge for paediatricians. This article aims to guide physicians in the management, diagnosis and follow up of children with suspected pneumonia, as well as discuss future developments in this ﬁeld. Keywords chest infection; childhood; lower respiratory tract infection; paediatric; pneumonia Introduction Community-acquired pneumonia remains the leading cause of death in children between the ages of 28 days and 5 years.1 Pneumonia affects children globally, although is most prevalent with highest mortality in sub-Saharan Africa and lower socioeconomic regions where vaccines are less accessible.2 Vaccination is a cost-effective strategy in preventing death from pneumonia2 and the introduction of the primary childhood vaccine program in the United Kingdom (UK) significantly reduced the incidence of pneumonia.3 What causes pneumonia? Community-acquired pneumonia can have bacterial, viral and fungal causes (see Table 1). Viral pathogens have been identified as the most common aetiology.4 These include Respiratory Syncytial Virus (RSV), Rhinovirus, Influenza, Parainfluenza, Human Metapneumovirus (hMPV) and Adenovirus. Cytomegalovirus (CMV) related pneumonia also needs to be considered in immunosuppressed patients, particularly those with underlying HIV infection. Although viral infections are the more common cause, bacterial infections are considered the more likely to cause severe disease and are responsible for up to 64% of pneumonia-related deaths.5 Globally, Streptococcus pnuemoniae and Haemophilus Ellen Crame MB ChB MRCPCH Paediatric Registrar, Royal Belfast Hospital for Sick Children (Belfast HSC Trust), UK. Conﬂicts of interest: none declared. Michael D Shields MB ChB MD FRCPCH Professor of Child Health, Queen’s University Belfast and Consultant Paediatrician, Royal Belfast Hospital for Sick Children (Belfast HSC Trust), UK. Conﬂicts of interest: none declared. Patrick McCrossan MB BCh BAO MRCPCH MD MSc Academic Clinical Lecturer, Queen’s University Belfast and Paediatric Registrar, Royal Belfast Hospital for Sick Children (Belfast HSC Trust), UK. Conﬂicts of interest: none declared. PAEDIATRICS AND CHILD HEALTH 31:6 250 Ó 2021 Elsevier Ltd. All rights reserved. PERSONAL PRACTICE grunting breathing and apnoea.1 Conversely, in older children more common symptoms are breathlessness, pleuritic chest pain, abdominal pain and headache. Clinical examination signs include decreased breath sounds and focal crepitations on auscultation. These are very sensitive markers of disease but have a low specificity and are at times subjective depending on the examiner. Tachypnoea and hypoxaemia also have high sensitivity for predicting the presence of a pneumonia in children of all ages and respiratory rate in particular can be a very valuable sign in guiding diagnosis and raising suspicion of disease.3 Conversely, children with wheeze and lowgrade fever typically do not have pneumonia.3 Where the diagnosis of pneumonia is being considered it is very important to carefully percuss the chest. Whilst a dull note alone will be often heard (or felt) in a child with a localised pneumonia, a stony dull note should alert the clinician to the possibility of a pleural effusion or empyema. As seen in Table 1, pneumonia can be caused by bacteria, fungus and viruses and it is very difficult to clinically differentiate between the underlying causes. However, a higher index of suspicion for bacterial infection should be considered in children presenting with persistent fever, breathlessness and increased work of breathing in the absence of wheeze.3 Figure 1 Bronchopneumonia. influenzae remain the most common pathogens. In areas with good pneumococcal conjugate (PCV) and H. influeznae B (Hib) vaccine coverage, Staphylococcus aureus and H. influenzae non-B type are the most prolific. Atypical pneumonias such as Mycoplasma and Chlamydia account for 27e36% of children admitted with bacterial pneumonia admitted to hospital5 (Atypical pneumonia is caused by organisms which are difficult to detect on traditional gram stain and culture methods). This may be due to the higher rates of hospital admission in the atypical subtypes due to failure of first line antibiotics. In areas where there are higher rates of tuberculosis (TB), or travel and immigrations from these areas, TB needs to be considered as a potential cause. Fungal causes are particularly important to keep in mind when assessing immunosuppressed patients, Pneumocystis (PCP) being the most common cause in HIV infected children. Investigations There are no investigations recommended for children with pneumonia who can be safely managed in the community. For those requiring secondary care assessment and admission to hospital, the physician may consider the following: Microbiological tests Sputum gram stain and culture is a useful test to determine the underlying bacterial causative organism. However, sputum samples are notoriously difficult to obtain in younger children and take several days to culture. They are particularly useful for the child who is severely unwell or not responding to treatment, in order to target antimicrobial therapy. Also, if admitted to the Intensive Care Unit, a bronchoalveolar lavage (BAL) sample is readily attainable via their endotracheal tube. Nasopharyngeal aspirates (NPA) can be sent for viral polymerase chain reaction (PCR). NPA are sensitive for detecting the presence of viruses but are not adequate for determining bacterial causes as the presence of normal nasal bacterial flora affects the interpretation. Rapid detection of the capsular polysaccharide (CPS) antigen of Streptococcus pneumoniae from urine samples has shown some promise with a high sensitivity and negative predictive value for detecting pneumococcal infection. However, its low specificity undermines its clinical utility.6 How does pneumonia in children present? The symptoms of pneumonia are often nonspecific and can be very wide ranging, making it a potentially challenging condition to diagnose. Symptoms also vary with age, although the most accepted common presenting features of pneumonia in all age groups include fever, cough, rhinorrhoea, dyspnoea, malaise and lethargy. Symptoms in infants can include reduced feeding, Imaging The British Thoracic Society (BTS) guidelines state that, ‘children with symptoms and signs suggesting pneumonia who are not admitted to hospital should not routinely have a chest X-ray’.3 Chest radiographs should not be considered a routine investigation for children with suspected pneumonia, nor is it necessary to make the diagnosis. Reviewing the literature on studies of chest x-rays, there can be no Figure 2 Lobar pneumonia. PAEDIATRICS AND CHILD HEALTH 31:6 251 Ó 2021 Elsevier Ltd. All rights reserved. PERSONAL PRACTICE Management The first step in managing children with pneumonia is deciding whether or not they can be managed safely in the community, or whether they need referring to a hospital. A thorough assessment of disease severity is needed on first presentation, with the premise that previously well children with mild disease are best managed at home. An assessment of severity will also influence the decision to investigate and initiate treatment, as well as guide the duration of treatment and level of medical and nursing care required in the hospital setting. The initial assessment of a child presenting with infective symptoms will normally take place in the primary care or emergency department setting. Doctors will assess children based on their clinical presentation but will also need to consider associated risk factors. Underlying health conditions and the social background of the child can impact on the ability for the condition to be well managed in the community. Children with complex needs and chronic underlying lung conditions may be more vulnerable to severe disease and may have a lower respiratory reserve. As a result, there is a lower threshold for initiation of antibiotic treatment and admission to hospital. Unlike the CURB 65 score in adults, there is no reliable assessment tool for scoring severity of disease in children.3 As a result, clinical markers of severity (see Table 2) remain the gold standard for assessing children that need hospital care. One of the most important measures to guide the need for admission to hospital is oxygen saturations, with hypoxaemia being a sensitive indicator of disease severity and prognosis.11 Also, tachypnoea correlates with hypoxaemia and so the respiratory rate requires careful assessment. The severely unwell child may require admission to the Paediatric Intensive Care Unit (PICU). The two main scenarios where PICU is indicated are when the pneumonia is severe enough to cause respiratory failure, requiring ventilatory support, or when the pneumonia is complicated by septicaemia. The diagnosis of respiratory failure is made following blood gas analysis. In children outside of the PICU setting, capillary or venous blood gases are most commonly used as arterial sampling is painful and very challenging in smaller children who do not have an arterial catheter. Respiratory failure would be indicated by low PaO2 readings and a high PaCO2 which may indicate the need for respiratory support and thus referral to a high dependency unit. Septicaemia may present as tachycardia, tachypnoea, hypoxaemia, signs of shock or recurrent apnoea with irregular breathing patterns. Figure 3 Round pneumonia.20 Source: reproduced from reference 20 with permission of Springer-Verlag 2010. significant links made between radiological findings and aetiology.3 The finding on chest x-rays also play no significant role in guiding the management of the pneumonia when the decision whether to treat with antibiotics is based on clinical findings and the response of symptoms to treatment.7 In addition, chest x-rays can be challenging to interpret, and findings are often subjective. The interpretation of x-rays is limited by the quality of the film and dependant on the expertise of the reader.8 Many studies have demonstrated significant variability and discrepancy between chest X-ray findings when interpreted by both radiologists and clinicians.8 However, chest x-rays do play a role when complications of pneumonia are suspected. Chest X-ray should be considered where symptoms are persistent and where there is an inadequate response to treatment within 72 hours.8 Blood tests Collating the data from multiple studies, the BTS concluded that, ‘acute phase reactants are not of clinical utility in distinguishing viral from bacterial infections and should not routinely be tested’.5 Both viral and bacterial infections can cause a rise in C Reactive Protein (CRP) and as a result the CRP should not influence the decision to treat for bacterial illness. However, CRP does play a role when complications are suspected, and a rising CRP may be an indication for more complex disease not improving with existing treatment. Neither a raised white cell count (WCC) nor erythrocyte sedimentation rate (ESR) has been proven to differentiate between viral and bacterial aetiologies.9 Procalcitonin (PCT) is released as part of the proinflammatory response of the innate immune system. It reaches detectable leaves at a faster rate than other inflammatory markers such as CRP and is not raised by viruses or collagen vascular diseases. A study by Baumann et al. suggests the elevated PCT is a good marker for pneumococcal infection and as a result, elevated PCT could be used to guide the treatment with antibiotics in children with a suspected diagnosis of pneumonia.10 PAEDIATRICS AND CHILD HEALTH 31:6 Treatment For children that do not warrant hospital admission, robust safety netting advice should be implemented to ensure that parents are aware of the signs of worsening disease, as discussed above. The mainstay of hospital treatment is supportive management. This may involve oxygen therapy if pulse oximetry reveals oxygen saturations lower than 92%.3 Intravenous fluids may be indicated when the child is struggling to maintain oral input due to breathlessness and fatigue, to prevent dehydration. Nasogastric tubes, although useful for providing hydration in many scenarios, should be avoided where possible in smaller children as 252 Ó 2021 Elsevier Ltd. All rights reserved. PERSONAL PRACTICE Common pathogens causing pneumonia in children Age Bacteria Viruses <20 days 3 weekse3 months E. coli, Group B Streptococcus, Listeria Chlamydia trachomatis, Streptococcus pneumoniae, Pertussis, Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis Streptococcus pneumoniae, Mycoplasma, Haemophilus influenzae, Staphylococcus aureus Streptococcus pneumoniae, Mycoplasma, Staphylococcus aureus, Tuberculosis Herpes simplex virus, Cytomegalovirus Adenovirus, respiratory syncytial virus, parainfluenza, influenza 4 monthse5 years >5 years Adenovirus, rhinovirus, influenza, parainfluenza, varicella zoster, respiratory syncytial virus Adenovirus, Epstein Barr virus, influenza, rhinovirus Table 1 to play a role in airway clearance in some children with complex needs who may struggle to independently clear secretions. In addition, where acute airway collapse is secondary to mucoid secretions causing plugging in the bronchi, assisted airway clearance will again be an important part of the management strategy. The world health organisation (WHO) defines pneumonia as, ‘the presence of either fast breathing or lower chest wall indrawing where the child’s chest moves in or retracts during inhalation.1’ The WHO states that due to the high mortality and morbidity rates worldwide, a child with suspected pneumonia should be treated with antibiotic therapy. This WHO definition of pneumonia was developed in order to be easily implemented by primary health care workers in the developing world to guide their use of prescribing antibiotics and thus prevent the serious sequelae of what is the most common cause of serious illness and death in young children worldwide. This was successful and resulted in a significant reduction in all-cause mortality for children. However, such high sensitivity comes at the cost of specificity, failing to distinguish between bacterial and viral causes. Indeed, research into use of the WHO guidelines in low-income countries has identified overdiagnosis of pneumonia in cases of wheezing, with consequent underdiagnosis of asthma, leading to significant respiratory morbidity and, perhaps, even mortality.13 As previously discussed, viral aetiology is more frequent than bacterial and there is no evidence to support that either chest Xray findings or inflammatory markers can reliably distinguish between the two. There has been much consideration given to the extensive use of antibiotics and the economic and health burden that results.14 BTS guidelines state that in a child under two years with mild symptoms, the cause is most likely to be viral in nature.3 Where the child appears acutely unwell, immediate administration of antibiotics is recommended, however it may be reasonable to carefully consider the use of antibiotics in mild disease.14 If deciding upon prescribing antibiotics, Amoxicillin is recommended as first line treatment of lower respiratory tract infection, as it has effective coverage against the most common pathogens in children.3 BTS guidance states that oral amoxicillin should be used in the first instance though there may be local microbiological guidelines in place depending on the prevalence of antibiotic they can cause further breathing compromise by obstructing the smaller nasal passages.3 With the use of intravenous fluids comes the risk of electrolyte imbalance, made more pronounced in pneumonia by the potential development of the syndrome of inappropriate anti-diuretic hormone (SIADH). Therefore, electrolyte and sodium monitoring are required to prevent hyponatraemia in instances where prolonged intravenous fluids are administered. Chest physiotherapy is not felt to be beneficial in children with uncomplicated pneumonia. Chest physiotherapy may potentially prolong fever duration and exacerbate breathing difficulties12 and is not recommended as part of management for children with pneumonia by the British Thoracic Society. Chest physiotherapy, along with the use of mucolytic agents, continues Clinical indicators of severity in childhood pneumonia5 Mild/moderate Severe Temp >38.5 C RR >70 breaths/minute Moderate/severe recession Cyanosis Intermittent apnoea Poor feeding Capillary refill time >2 second Tachycardia Temp >38.5 C Older children Temp <38.5 C RR <50 breaths/minute RR >50 breaths/minute Mild breathlessness Severe difficulty in No vomiting breathing Nasal flaring Grunting Cyanosis Signs of dehydration Tachycardia Capillary refill time >2 seconds Infants Temp <38.5 C RR <50 breaths/minute Mild recession Taking full feeds Table 2 PAEDIATRICS AND CHILD HEALTH 31:6 253 Ó 2021 Elsevier Ltd. All rights reserved. PERSONAL PRACTICE resistant pathogens. Enteral administration of antibiotics is as effective as intravenous. This reduces the need for cannulation and can be continued in the community effectively.3 Intravenous antibiotics may be required where complications are suspected or when the enteral route is poorly tolerated.3 Macrolide antibiotics (e.g. azithromycin, clarithromycin) are second line treatment if there is an unsatisfactory response to amoxicillin or in instances where an atypical pneumonia is suspected. Co-amoxiclav may be a better first line antibiotic in children with complex needs associated with a poor cough and swallowing dysfunction for whom anaerobic bacteria may be easily aspirated. Figure 4 illustrates a suggested stepwise approach to the diagnosis and management of children with suspected pneumonia. sepsis in association with a pleural collection despite chest tube drainage and antibiotics.15 Necrotising pneumonia and lung abscess Lung abscess is a collection of pus within the lung tissue and is considered a very rare but significant complication in children, due to its high rates of mortality and long-term implications. This occurs when there is liquefactive necrosis (in which the lung tissue is digested by hydrolytic enzymes resulting in a circumscribed lesion containing pus) of lung tissue (secondary to infection) causing the formation of a cavity containing inflammatory cells, bacteria and frank pus. Lung abscess may be identified on chest X-ray by the presence of a cavity with an air-fluid level. A bronchopleural fistula may form, leading the abscess into the pleural space with subsequent formation of an empyema or pneumothorax. Treatment includes a prolonged course of intravenous antibiotics. Percutaneous CT guided drainage of the abscess may be required and in cases where there is progressive lung parenchymal necrosis, segmental or lobar resection may be necessary. Long term complications of these conditions can occur causing bronchiectasis, scarring and chronic cough.16 Complications Most children with community-acquired pneumonia go on to make a full recovery. However, both pulmonary and systemic complications occur in around 3%,5 resulting in significant morbidity and mortality. Regular reassessment of a child with pneumonia is recommended, including for children managed in the community. Increased effort of breathing, agitation and persistent or swinging fevers should prompt parents to return for further assessment and it is important that this information is provided. Pulmonary complications include parapneumonic effusion, empyema and lung abscess. Systemic complications can include multi organ failure, metastatic infection, bacteraemia and Acute Respiratory Distress Syndrome (ARDS). Pneumatocoele Pneumaotocoeles are intrapulmonary air-filled cysts. As a consequence of pneumonia, the bronchus may become narrowed by inflammatory exudates, leading to the formation of a ball valve that causes distal dilatation of the alveoli as air is able to enter the cystic space but not leave it. Pneuomatocoeles appear as thin-walled cystic spaces containing air (see Figure 6). If they are imaged during the early stage of the infection, they may have surrounding consolidation which makes it difficult to distinguish from an abscess. The main significance of pneumatocele is that it must be distinguished from other cavitary pulmonary lesions such as an abscess in order to avoid unnecessary invasive interventions. Most pneumatocoeles spontaneously resolve over time (usually by six weeks) following appropriate treatment of the underlying infection. Decompression is considered when the pneumatocoele is large enough to compress adjacent lung and mediastinal structures. Empyema and pleural effusion A pleural effusion is a collection of fluid in the space between the lungs and the chest wall (the pleural space) (see Figure 5). When this pleural fluid is pus or infective then it is termed an empyema. They occur in 1% of cases of community-acquired pneumonia. However, in patients needing hospital admission this may be up to 40%.5 Empyema should be suspected if fevers are persisting on adequate treatment for 48 hours, or there has been 7 days of persistent fever. The investigation of choice is a chest X-ray to identify fluid in the pleural space and ultrasound to estimate the volume of the fluid present. Intravenous antibiotic therapy is necessary in these patients to provide a broader coverage and higher penetrance of the pleural space.3 Local microbiology advice should be sought to guide the antimicrobial treatment but should ensure cover for S. pneumoniae. These children often require a prolonged course of enteral antibiotics (1e4 weeks), even once the intravenous antibiotics have been discontinued. Effusions which compromise respiratory function should not be managed by antibiotics alone and early insertion of a chest drain should be considered. Chest drains should be placed under ultrasound guidance and a small bore (including pig tail) drain should be considered ahead of large bore surgical drains where possible. Intrapleural fibrinolytics shorten hospital stay and are recommended for any complicated parapneumonic effusion. Patients should be considered for surgical treatment (including video assisted thoracoscopy (VATS)) if they have persistent PAEDIATRICS AND CHILD HEALTH 31:6 Follow up BTS guidelines do not recommend routine follow up imaging in uncomplicated community-acquired pneumonia. If complications arise such as empyema or persistent lobar collapse, then this may warrant follow up X-ray.5 Interestingly, children with a round pneumonia who respond to antibiotics do not require follow up radiograph (unlike the management of this phenomenon in adults).17 Future developments Bedside ultrasound Ultrasound is diagnostic tool currently used in many paediatric intensive care settings and could reduce the need for radiation exposure and chest x-rays in the future. The benefits of ultrasound include the absence of radiation and also high 254 Ó 2021 Elsevier Ltd. All rights reserved. PERSONAL PRACTICE Figure 4 Diagnosis and treatment algorithm for childhood pneumonia. PAEDIATRICS AND CHILD HEALTH 31:6 255 Ó 2021 Elsevier Ltd. All rights reserved. PERSONAL PRACTICE discriminate between viral and bacterial causes via blood sampling.19 Conclusion Paediatric pneumonia is a common but potentially very serious illness. The major challenge for the physician is in determining between viral and bacterial aetiology in order to improve antimicrobial stewardship but also to recognise the unwell child who would require hospital admission for further management. Until more sensitive tests are available, physicians will continue to depend on their clinical acumen to make these difficult decisions. A REFERENCES 1 Organisation WH. Pneumonia. Available from: https://www.who. int/news-room/fact-sheets/detail/pneumonia. 2 Shiri T, McCarthy ND, Petrou S. The impact of childhood pneumococcal vaccination on hospital admissions in England: a whole population observational study. BMC Infect Dis 2019; 19: 1e8. 3 Oliwa JN, Marais BJ. Vaccines to prevent pneumonia in children ea developing country perspective. Paediatr Respir Rev 2017; 22: 23e30. 4 Marangu D, Zar HJ. Childhood pneumonia in low-and-middleincome countries: an update. Paediatr Respir Rev 2019; 32: 3e9. 5 Harris M, Clark J, Coote N, et al. British Thoracic Society guidelines for the management of community acquired pneumonia in children: update 2011. Thorax 2011; 66(Suppl 2): ii1e23. 6 Domínguez J, Blanco S, Rodrigo C, et al. Usefulness of urinary antigen detection by an immunochromatographic test for diagnosis of pneumococcal pneumonia in children. J Clin Microbiol 2003; 41: 2161e3. 7 O’Grady K-AF, Torzillo PJ, Frawley K, Chang AB. The radiological diagnosis of pneumonia in children. Pneumonia 2014; 5: 38e51. 8 de Benedictis FM, Kerem E, Chang AB, Colin AA, Zar HJ, Bush A. Complicated pneumonia in children. Lancet 2020; 396: 786e98. € m E, Mertsola J, 9 Virkki R, Juven T, Rikalainen H, Svedstro Ruuskanen O. Differentiation of bacterial and viral pneumonia in children. Thorax 2002; 57: 438e41. 10 Baumann P, Baer G, Bonhoeffer J, et al. Procalcitonin for diagnostics and treatment decisions in pediatric lower respiratory tract infections. Front Pediatr 2017; 5: 183. 11 Smyth A, Carty H, Hart C. Clinical predictors of hypoxaemia in children with pneumonia. Ann Trop Paediatr 1998; 18: 31e40. 12 Gilchrist FJ. Is the use of chest physiotherapy beneﬁcial in children with community acquired pneumonia? Arch Dis Child 2008; 93: 176e8. 13 Østergaard MS, Nantanda R, Tumwine JK, Aabenhus R. Childhood asthma in low income countries: an invisible killer? Prim Care Respir J 2012; 21: 214e9. 14 Weinberger M. Antibiotics for community-acquired pneumonia: only sometimes!. Pediatric Pulmonology 2019; 54(8): 1106. 15 Balfour-Lynn IM, Abrahamson E, Cohen G, et al. BTS guidelines for the management of pleural infection in children. Thorax 2005; 60(suppl 1): i1e21. 16 Masters IB, Isles AF, Grimwood K. Necrotizing pneumonia: an emerging problem in children? Pneumonia 2017; 9: 11. Figure 5 Pleural effusion. availability of equipment which can be used effectively at the bedside. Studies have shown that lung ultrasound may be able to replace chest x-rays as the imaging modality of choice in pneumonia, with no change to clinical outcome. Ultrasound equipment is also much more easily obtained and supplied to resource poor areas, when compared to the machinery required to perform chest x-rays. As a result, the use of ultrasound to diagnose pneumonia is an exciting prospect in developing countries.18 Improved laboratory tests The ability to determine the causative organism quickly and effectively in cases of pneumonia would allow antimicrobial treatment and duration of treatment to be guided more effectively. It would also identify the children at risk of severe disease and the development of complications. An increasing area of interest is the use of blood specimens to identify a host transcriptional signature associated with specific pathogens. Recent studies have shown encouraging results in distinguishing between influenza and bacterial pathogens from blood specimens and it is hoped that in time pathogen signatures may be used to Figure 6 Pneumatocoele evolving out of extensive bibasal consolidation in a patient with immune deﬁciency. PAEDIATRICS AND CHILD HEALTH 31:6 256 Ó 2021 Elsevier Ltd. All rights reserved. PERSONAL PRACTICE 17 McCrossan P, McNaughten B, Shields M, Thompson A. Is follow up chest X-ray required in children with round pneumonia? Arch Dis Child 2017; 102: 1182e3. 18 Pervaiz F, Hossen S, Chavez MA, et al. Training and standardization of general practitioners in the use of lung ultrasound for the diagnosis of pediatric pneumonia. Pediatr Pulmonol 2019; 54: 1753e9. 19 Zar HJ, Andronikou S, Nicol MP. Advances in the diagnosis of pneumonia in children. BMJ 2017; 358: j2739. 20 Restrepo R, Palani R, Matapathi UM, Wu Y-Y. Imaging of round pneumonia and mimics in children. Pediatr Radiol 2010; 40: 1931e40. PAEDIATRICS AND CHILD HEALTH 31:6 FURTHER READING Balfour-Lynn IM, Abrahamson E, Cohen G, et al. BTS guidelines for the management of pleural infection in children. Thorax 2005; 60(suppl 1): i1e21. Harris M, Clark J, Coote N, et al. British Thoracic Society guidelines for the management of community acquired pneumonia in children: update 2011. Thorax 2011; 66(Suppl 2): ii1e23. O’Grady K-AF, Torzillo PJ, Frawley K, Chang AB. The radiological diagnosis of pneumonia in children. Pneumonia 2014; 5: 38e51. Organisation WH. Pneumonia. Available from: https://www.who.int/ news-room/fact-sheets/detail/pneumonia. Weinberger M. Antibiotics for community-acquired pneumonia: only sometimes!. Pediatric Pulmonology 2019; 54(8): 1106. 257 Ó 2021 Elsevier Ltd. All rights reserved.