The outcomes of COVID‐19 pneumonia in children—clinical, radiographic, and pulmonary function assessment

Abstract

Objectives

The goal of this study was to assess the pulmonary sequelae of COVID‐19 pneumonia in children.

Study Design

Children (0–18 years old) diagnosed with COVID‐19 pneumonia hospitalized between March 2020 and March 2021 were included in this observational study. All children underwent follow‐up visits 3 months postdischarge, and if any abnormalities were stated, a second visit after the next 3 months was scheduled. Clinical assessment included medical history, physical examination, lung ultrasound (LUS) using a standardized protocol, and pulmonary function tests (PFTs). PFTs results were compared with healthy children.

Results

Forty‐one patients with COVID‐19 pneumonia (severe disease n = 3, mechanical ventilation, n = 0) were included in the study. Persistent symptoms were reported by seven (17.1%) children, the most common was decreased exercise tolerance (57.1%), dyspnea (42.9%), and cough (42.9%). The most prevalent abnormalities in LUS were coalescent B‐lines (37%) and small subpleural consolidations (29%). The extent of LUS abnormalities was significantly greater at the first than at the second follow‐up visit (p = 0.03). There were no significant differences in PFTs results neither between the study group and healthy children nor between the two follow‐up visits in the study group.

Conclusions

Our study shows that children might experience long‐term sequelae following COVID‐19 pneumonia. In the majority of cases, these are mild and resolve over time.

1. INTRODUCTION

Due to its rapid human‐to‐human transmission, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has to date infected over 600 million people, and caused over 6.5 million deaths as of the end of October 2022. ¹ World Health Organization (WHO) declared the novel 2019 SARS‐CoV‐2 disease (COVID‐19) pandemic in March 2020. After over 2 years and despite increasing vaccination rates, it is still far from ended.

The spectrum of disease ranges in severity from an asymptomatic carriage and mild respiratory infection to respiratory failure with a high mortality rate. ² Morbidity, severity, and mortality rise steeply with older age and comorbidities. ³ , ⁴ In immunologically naïve adults, a high proportion of severe pneumonia and acute respiratory distress syndrome requiring intensive care admission and invasive mechanical ventilation was observed since the onset of the pandemic. ⁵ , ⁶

Conversely, children seem to be less affected than adults with 90%–95% presenting with asymptomatic to mild or moderate clinical patterns and exhibiting better prognosis with lower hospitalization and mortality rates, 1% and 0.1%–0.69% respectively. ⁷ , ⁸ , ⁹ , ¹⁰ , ¹¹ , ¹² Predominant complaints include fever, malaise, and mild respiratory symptoms, but children are not spared severe COVID‐19 manifestations and pediatric cases of severe pneumonia, respiratory distress and deaths have been reported in all ages. ⁷ , ⁹ , ¹⁰ , ¹³ , ¹⁴ , ¹⁵ , ¹⁶ , ¹⁷

Although rare in children, COVID‐19 pneumonia varies in severity from asymptomatic or paucisymptomatic disease to a factor significantly increasing the length of hospital stay. ¹⁶ , ¹⁸ , ¹⁹ The diagnosis of COVID‐19 pneumonia is based on clinical symptoms, nasal swab results, and radiological findings. The main features of chest radiography or computed tomography studies in children are bronchial thickening, ground‐glass opacities, and consolidations. ¹³ , ¹⁶ , ²⁰ Noteworthy, lung ultrasound (LUS) has been successfully used as a diagnostic, prognostic, and monitoring tool in pediatric COVID‐19 patients. ²¹ While almost all children with COVID‐19 pneumonia experience favorable outcomes, long‐term consequences are possible, similar to other viral pneumonia.

Emerging data suggest that children with SARS‐CoV‐2 infection can present with prolonged symptoms for weeks after recovery. ²² , ²³ , ²⁴ , ²⁵ However, aside from Pediatric Inflammatory Multisysytem Syndrome temporally associated with COVID‐19 (PIMS‐TS)/Multisystem Inflammatory Syndrome in Children (MIS‐C), data on long‐term COVID‐19 consequences in children are limited. ²⁶ In particular, the burden of COVID‐19 pneumonia in children has not been precisely defined. As far as we know, there are no long‐term follow‐up studies published to date assessing clinical, imaging, and pulmonary function outcomes in children following COVID‐19 pneumonia.

Our study aimed to assess the possible sequelae of COVID‐19 pneumonia in children posthospital discharge.

2. MATERIALS AND METHODS

Consecutive children (0–18 years old) diagnosed with COVID‐19 pneumonia and hospitalized between March 2020 and March 2021 in the Department of Pediatric Pneumonology and Allergy and in the Department of Children's Infectious Diseases of the Medical University of Warsaw were included. The diagnosis of COVID‐19 pneumonia was made on the basis of clinical symptoms and the presence of inflammatory infiltrates on chest radiography in children with a positive result of the reverse transcription real‐time fluorescence polymerase chain reaction test for SARS‐CoV‐2. The severity of COVID‐19 pneumonia was classified according to WHO. ²⁷

All children underwent follow‐up in the Department of Pediatric Pneumonology and Allergy of the Medical University of Warsaw. Clinical assessment included medical history, physical examination, LUS, and pulmonary function tests (PFTs). The first follow‐up visit was performed 3 months after initial hospital discharge. Patients with abnormal findings were invited for a second follow‐up visit after the next 3 months.

2.1. Lung ultrasound

Patients underwent LUS using Philips Epiq 5G with an L12‐5 MHz linear transducer and a 5‐1 MHz convex probe by using a specific lung software setting. LUS was performed by two pediatricians with more than 5 years of experience in pediatric pulmonology and point‐of‐care LUS, who were blinded to the initial chest radiography results.

Lung evaluation was performed in the sitting position in older children and in the supine position in infants and noncooperating children, and all lung areas were scanned transversely and longitudinally. The following variables were assessed following a standardized acquisition protocol according to Soldati et al. ²⁸ : A‐line, normal lung sliding, separate B‐lines, coalescent B‐lines, patchy areas of the white lung, irregular pleural line, subpleural consolidations (small ≤1 cm, large >1 cm), air bronchogram, and pleural effusion.

2.2. Pulmonary function tests

All eligible patients underwent PFTs including spirometry, body plethysmography, diffusing lung capacity for carbon monoxide (DLCO), and impulse oscillometry (IOS). All procedures were performed according to American Thoracic Society/European Respiratory Society recommendations. ²⁹ Spirometry and IOS were performed using the Vyntus IOS (CareFusion) and body plethysmography and DLCO using the Master Screen Body (CareFusion).

The following parameters were recorded: spirometry—forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and FEV1/FVC ratio; body plethysmography—specific airway resistance (sRaw), residual volume (RV), total lung capacity (TLC); and DLCO. ³⁰ Reference equations from the Global Lung Function Initiative were used to calculate z scores. ³¹ The measured IOS parameters included: respiratory resistance at 5 and 20 Hz (R5 and R20), reactance at 5 Hz (X5), frequency dependence of resistance (R5–R20), and area under reactance curve (AX). For data analysis, the Dencker et al. ³² reference values were used.

All measured parameters were presented as z scores. The exceptions were R5–R20 and AX, which were presented only as absolute values due to the lack of reference equations. Z score values below −1645 or above 1645 were considered abnormal.

An obstructive ventilatory defect was defined as FEV1/FVC ratio z score lower than −1645, a restrictive ventilatory defect as TLC z score lower than −1645, and air trapping as an RV%TLC z score higher than 1,645. DLCO values were considered impaired when z score was <−1645 or >1645. Increased respiratory resistance was diagnosed when z score of sRaw or R5 was >1645. ³³

The results of spirometry, body plethysmography, and oscillometry were compared with age‐ and sex‐matched healthy children.

Ethics approval for this study was provided by the Medical University of Warsaw Ethics Committee (AKBE/65/2021). Before enrollment, written informed consent was obtained from the parents or legal guardians of each participant and from patients aged 16 years and older.

2.3. Statistical analysis

Statistical analysis was performed with GraphPad Prism 9 software. The results were presented as medians and interquartile ranges (IQRs). Comparisons between the study group and healthy children were performed using Mann–Whitney's U test for interval variables and the chi‐square test to compare proportions. Wilcoxon matched‐pairs signed rank test was used to compare repeated measurements in the study group. To find possible correlations between LUS and PFTs parameters Spearman rank correlation test was used. The two‐tailed significance level was set at p < 0.05.

The results of this study are reported according to STROBE guidelines for reporting of observational research. ³⁴

3. RESULTS

Between March 2020 and March 2021, 460 children diagnosed with COVID‐19 were hospitalized in both departments. A total of 41 patients diagnosed with COVID‐19 pneumonia were included in this study, 18 (43.9%) boys and 23 (56.1%) girls. All subjects presented with moderate to severe COVID‐19 disease. There were three cases of severe COVID‐19 pneumonia. All of them required high‐flow oxygen therapy and were treated with glucocorticoids, two patients received remdesivir. No patient required mechanical ventilation. Of the four (9.8%) children with dyspnea, all were teenagers, three with obese, and one with overweight, and no other comorbidities were reported. Study group characteristics and acute COVID‐19 pneumonia symptoms are provided in Table 1.

Table 1.

Study group characteristics and presenting symptoms

Demographic and clinical data	Study group N = 41 (% or median IQR)
Males, n (%)	18 (43.9)
Females, n (%)	23 (56.1)
Age, years, median (IQR)	3.75 (0.7–12.9)
Height centile, median (IQR)	76 (37.2–91.7)
Body mass centile, median (IQR)	73 (36–94)
BMI centile, median (IQR)	53.5 (23.7–94.2)
Obesity (according to WHO), %	7.3
Cough, %	63.4
Fever, %	61
Fatigue, %	41.5
Nasal congestion or discharge, %	34.1
Diarrhea or vomiting, %	31.7
Dyspnea, %	9.8
Muscle pain, %	7.3
Chest pain, %	7.3
Sore throat, %	7.3
Headache, %	7.3
Lack of appetite, %	4.9
Anxiety, %	4.9
Hemoptysis, %	2.4
Earache, %	2.4
Loss of smell and taste, %	2.4

Abbreviations: IQR, interquartile range; n, number; WHO, World Health Organization.

3.1. Persistent clinical symptoms

At each control visit, all attending patients underwent a clinical assessment and LUS. LUSs were performed only in cooperating children. The patient flowchart including information on performed examinations is presented in Figure 1.

Figure 1.

Diagram of included patients and diagnostic procedures at each follow‐up visit. DLCO, diffusing lung capacity for carbon monoxide; IOS, impulse oscillometry; LUS, lung ultrasound.

On the first follow‐up visit, persistent symptoms were present in seven (17.1%) children. The most commonly reported were decreased exercise tolerance (57.1%), dyspnea (42.9%), and cough (42.9%). Other included fatigue (28.6%), sleeping difficulties (14.3%), impaired concentration (14.3%), and lack of appetite (14.3%). We did not observe significant abnormalities in the physical examination or oxyhemoglobin saturation.

A total of 19 out of 27 invited patients attended the second follow‐up visit. Seven patients were lost to follow‐up due to nonmedical reasons. Two (10.5%) subjects reported persistent symptoms such as lack of appetite and exercise intolerance. Similar to the first follow‐up visit, the physical examination and oxyhemoglobin saturation were normal in all attending patients.

There were no cases of lower respiratory tract infections among the participants in the period between acute COVID‐19 and the second follow‐up visit.

3.2. Lung ultrasound

At the first follow‐up visit, 26 (63%) patients had abnormal LUS findings. The most common significant abnormalities observed were coalescent B‐lines (37%) and small subpleural consolidations (29%). At the second follow‐up visit, out of 19 patients, 14 (73.7%) had abnormalities in LUS. Again, the main findings were coalescent B‐lines (52.6%) and small subpleural consolidations (36.8%). All children with abnormal LUS findings at the second follow‐up visit presented LUS abnormalities also at the first follow‐up. The extent of LUS abnormalities was greater at the first than at the second follow‐up visit, as demonstrated by the median score according to Soldati et al., ²⁸ which was 4 (IQR: 2–5) and 2 (IQR: 0.5–5), respectively. This difference was statically significant (p = 0.03). All abnormalities observed in the LUS are presented in Table 2. Among patients with persistent clinical symptoms, abnormalities in LUS were present in 6 (85.7%) at the first follow‐up visit, and in 2 (100%) at the second follow‐up visit. The most common abnormalities stated were coalescent B‐lines and small subpleural consolidations.

Table 2.

Lung ultrasound results presented as % of patients

	First follow‐up visit (n = 41)	Second follow‐up visit (n = 19)
Separate B‐lines	39	21.1
Coalescent B‐lines	36.6	52.6
White lung sign	0	0
Irregular pleural line	14.6	10.5
Small consolidations	29.3	36.8
Large consolidations	0	0
Pleural effusion	2.4	5.3

Abbreviation: n, number.

3.3. Pulmonary function tests

At the first follow‐up visit, 15 (36.6%) patients performed spirometry, body plethysmography, and DLCO, and 17 (41.5%) patients performed IOS. There were no significant differences in spirometry, body plethysmography, and IOS results between the study group and healthy children. In the study group, one boy with untreated asthma presented an obstructive ventilatory defect. A restrictive ventilatory defect was present in three subjects, two with severe COVID‐19 pneumonia and one with a mild course of the disease. One patient had a decreased DLCO.

At the second follow‐up visit, 12 (63.2%) patients performed spirometry, body plethysmography, DLCO, and 13 (68.4%) patients performed IOS. There were no significant differences in PFTs results between the two follow‐up visits in our study group. An obstructive ventilatory defect was present in two patients, one previously mentioned boy with untreated asthma, and one girl with newly diagnosed asthma. A restrictive ventilatory defect was found again in three patients.

Among four patients with dyspnea during acute COVID‐19 pneumonia, we observed significant abnormalities in all three participants who were able to perform PFTs. One girl was not cooperating during PFTs and it was impossible to obtain acceptable and reproducible PFTs results. The most abnormal findings were reported in a 12‐year‐old boy with obesity who had a restrictive ventilatory defect, decreased FVC, decreased RV and RV/TLC ratio, and decreased DLCO. LUS results are shown in Tables 3 and 4.

Table 3.

PFTs results in the study group at two follow‐up visits

Parameter	First follow‐up visit median (IQR)	Second follow‐up visit median (IQR)	p
FEV1, z score	0.49 (−0.7 to 1.83)	−0.76 (−1.36 to 2.01)	NS
FVC, z score	0.3 (−0.77 to 1.67)	0.49 (−0.5 to 1.7)	NS
FEV1%FVC, z score	0.06 (−0.6 to 0.69)	0.04 (−1.05 to 0.64)	NS
sR eff, z score	2.72 (0.97–4.08)	2.75 (0.48–3.38)	NS
TLC, z score	0.43 (−1.07 to 1.41)	0.47 (−0.86 to 2.45)	NS
RV, z score	−1.26 (−1.96 to −0.07)	−0.09 (−2.34 to 1.3)	NS
RV%TLC, z score	−1.2 (−2.06 to 0.22)	−0.36 (−1.9 to 0.51)	NS
R 5 Hz, z score	0.13 (−0.42 to 0.47)	−0.1 (−0.54 to 0.08)	NS
X 5 Hz, z score	0.43 (−0.2 to 1.2)	0.43 (−0.42 to 1.11)	NS
Fres, z score	0.71 (−0.14 to 1.66)	0.71 (0.18−1.51)	NS
AX, kPa/L	1.02 (0.43–1.97)	1.32 (0.39−1.66)	NS
DLCO, z score	0.2 (−0.35 to 0.73)	0.18 (−0.84 to 0.61)	NS

Abbreviations: AX, reactance area; DLCO, diffusion lung capacity for carbon monoxide; FEV1, forced expiratory volume in 1 s; Fres, resonant frequency; FVC, forced vital capacity; IQR, interquartile range; NS, not statistically significant; PFT, pulmonary function test; R 5 Hz, resistance at 5 Hz; RV, residual volume; sR eff, specific effective airway resistance; TLC, total lung capacity; X5, reactance at 5 Hz.

Table 4.

Study group (first follow‐up visit) and healthy children, PFTs results comparison

Parameter	Study group median (IQR)	Healthy children median (IQR)	p
Age, months	162 (100.5–195.5)	156 (102–188.5)	NS
FEV1, z score	0.49 (−0.76 to 1.86)	0.32 (−0.31 to 1.04)	NS
FVC, z score	0.3 (−0.89 to 1.96)	0.34 (−0.53 to 0.92)	NS
FEV1%FVC, z score	0.06 (−0.61 to 0.75)	0.03 (−0.37 to 0.95)	NS
sR eff, z score	2.72 (0.34–4.1)	2.4 (1.19–3.13)	NS
TLC, z score	0.43 (−1.21 to 1.46)	−0.01 (−1.56 to 0.49)	NS
RV, z score	−1.26 (−2.05 to −0.06)	−1.06 (−2.72 to 0.16)	NS
RV%TLC, z score	−1.2 (−2.17 to 0.34)	−1.61 (−2.37 to 0.06)	NS
R 5 Hz, z score	0.13 (−0.44 to 0.48)	−0.01 (−0.96 to 0.13)	NS
X 5 Hz, z score	0.43 (−0.26 to 1.41)	0.63 (0.07–1.16)	NS
Fres, z score	0.71 (−0.17 to 1.67)	0.94 (0.2–1.8)	NS
AX, kPa/L	1.02 (0.36–2.05)	0.85 (0.33–1.08)	NS

Abbreviations: AX, reactance area; FEV1, forced expiratory volume in 1 s; Fres, resonant frequency; FVC, forced vital capacity; IQR, interquartile range; NS, not statistically significant; PFT, pulmonary function test; R 5 Hz, resistance at 5 Hz; RV, residual volume; sR eff, specific effective airway resistance; TLC, total lung capacity; X 5, reactance at 5 Hz.

There were no significant correlations between LUS Soldati score and PFTs results (spirometry, body plethysmography, IOS, DLCO).

4. DISCUSSION

The results of this prospective follow‐up study demonstrated that long‐term sequalae after COVID‐19 pneumonia are relatively common in children and adolescents. During follow‐up, the majority of patients had abnormal LUS findings. Approximately 20% of children presented prolonged symptoms, and abnormalities in PFTs were found predominantly in individuals recovering from severe illness. However, no significant differences in PFTs results were observed between COVID‐19 pneumonia convalescents and healthy children.

To the best of our knowledge, this is the first study assessing the consequences of microbiologically and radiologically confirmed COVID‐19 pneumonia in pediatric patients posthospital discharge, which is the major strength of our study. We followed up with patients up to 6 months after COVID‐19 pneumonia diagnosis and assessed their signs and symptoms on face‐to‐face visits. We performed a physical examination, LUS, and a broad spectrum of PFTs. Moreover, PFTs results were compared with healthy children. While increasing number of studies assessing children after SARS‐CoV‐2 infection in a longer time frame is being published, only a few implemented objective measures of pulmonary involvement, such as PFTs and LUS. ²³ , ³⁵ , ³⁶ , ³⁷

The epidemiological and clinical characteristics of COVID‐19 at the acute phase in children is well described, yet evidence on long‐term sequelae is still limited. Data on the adult population showed that even 60%–80% experience symptoms lasting weeks and months after initial diagnosis. ³⁸ , ³⁹ Such persistent signs and symptoms are described as long‐COVID, post‐COVID‐19 syndrome, or postacute sequelae of SARS‐CoV‐2. ⁴⁰ Apart from studies on PIMS‐TS/MIS‐C, an immune‐mediated disease occurring in a small proportion of pediatric patients (<0.1%) 2– 6 weeks following infection with SARS‐CoV‐2, the persistent post‐COVID‐19 symptoms in children have not gained much attention until the end of 2021. ⁴¹ Despite the first reports showing almost a complete recovery and no long‐COVID symptoms in children, ³⁵ , ⁴² emerging data indicate that persisting symptoms may affect more than 25% of pediatric COVID‐19 convalescents. ⁴³ , ⁴⁴ , ⁴⁵ However, due to the high heterogeneity of reported data (SARS‐CoV‐2 infection severity, case definition, study groups, and observation time), the precise prevalence of long‐COVID in children remains largely unknown and ranges from 1.8% to 96.6%. ²² , ²⁴ , ²⁵ , ³⁶ , ⁴¹ , ⁴⁶ , ⁴⁷ , ⁴⁸ , ⁴⁹ , ⁵⁰ , ⁵¹

In the present study, prolonged symptoms were present approximately in 1 in 5 patients after 3 months and in 1 in 20 patients after 6 months following a COVID‐19 pneumonia diagnosis. The most commonly observed persistent symptoms were decreased exercise tolerance (10%), dyspnea (7%), cough (7%), and fatigue (5%). Conversely, a recent review identified fatigue and neurocognitive disorders, such as headache, sleep disturbance, and concentration difficulties as the most prevalent persistent symptoms in children. ²⁶ Yet, among children with persistent respiratory symptoms, a significant proportion (50%–96.6%) suffer from dyspnea, approximately half from exertional limitation and cough, and 36%–60% experience severe limitations of daily activity. ²³ , ³⁶ , ⁵² Furthermore, some risk factors for persistent symptoms following SARS‐CoV‐2 infection in children have been recently identified. These include older age, increased body mass index, and allergic diseases. ²² , ²⁴ , ⁴⁵ , ⁵³ In particular, links between excessive weight and obesity and severe short‐term outcomes and postacute sequelae have been recognized. ²² , ³⁶ , ⁵⁴ In keeping with these reports, in our study group, we noticed pulmonary impairment in teenagers with obesity. However, our results cannot be directly compared to those presented above as we included only patients with COVID‐19 pneumonia (irrespective of prolonged symptoms).

LUS has been encouraged in pediatric COVID‐19 patients as a diagnostic modality not only during the initial workup but also in monitoring the infection. ³⁵ , ⁴² , ⁵⁵ , ⁵⁶ , ⁵⁷ , ⁵⁸ , ⁵⁹ In our study, the majority of patients presented with mild abnormalities that had a tendency to recede over time. Follow‐up studies utilizing LUS for the assessment of lung involvement specifically in children recovering from COVID‐19 pneumonia are not available, and those assessing children after SARS‐CoV‐2 infection are rare. Contrary to our findings, other follow‐up studies reported either LUS abnormalities in the minority of children or no abnormalities at all. In a study by Denina et al., ³⁵ 5 (20%) out of 25 children presented with a mild interstitial pattern and small subpleural consolidations 4 months after hospital discharge. In medium‐term observation of children following an asymptomatic or mildly symptomatic SARS‐CoV‐2 infection Bottino et al. ³⁷ detected no pulmonary involvement. The high prevalence of LUS abnormalities in our study may be explained by the fact that all the participants had confirmed COVID‐19 pneumonia, whereas other studies included also children with mild disease.

Pulmonary function showed no significant differences between the study group and healthy children. It is worth emphasizing, that our study is the first to compare the PFTs results of pediatric COVID‐19 survivors with healthy controls. While we observed a restrictive ventilatory defect and an abnormal DLCO in several patients, in the majority of participants, no abnormalities were detected. Of note, almost all severe SARS‐CoV‐2 survivors had abnormal spirometry and/or body plethysmography results. Additionally, the two patients with an obstructive ventilatory defect had asthma. Previous studies assessing pulmonary function following SARS‐CoV‐2 infection demonstrated normal spirometry, plethysmography, and diffusion studies in heterogenous groups of children. ³⁶ , ³⁷ In contrast, observations from Israel demonstrated that 45% of children with persistent cardiorespiratory symptoms had PFTs findings compatible with a mild obstructive pattern. ²³ Concordantly, most patients with dyspnea in our study presented abnormalities in PFTs. The comparison of our results with other studies is difficult since there are no studies implementing PFTs specifically in pediatric COVID‐19 pneumonia survivors. In adults, a relatively high prevalence of respiratory function impairment was reported. The most commonly observed abnormalities were altered diffusing capacity, restrictive pattern, and obstructive pattern found in 39%, 15%, and 7% of patients, respectively. ⁶⁰

The present study bears several limitations. First, the study group was relatively small. Second, not all participants were eligible to perform PFTs. Third, PFTs and LUS were not performed at the time of diagnosis due to epidemiological reasons, therefore no comparison with the acute disease was possible. Finally, only three patients in our study group had severe COVID‐19 pneumonia. Therefore, it has to be acknowledged, that our results may not reflect the true prevalence of persisting symptoms in children with severe COVID‐19 and should be interpreted with caution. Since we noted pulmonary impairment only in children with severe acute illness, this is surely the group of patients that merits further research.

5. CONCLUSION

The results of our study show that children might experience pulmonary sequelae following COVID‐19 pneumonia. However, in the majority of cases, these are mild and with a tendency to resolve over time. While only children with severe acute infection presented significant pulmonary impairment on follow‐up, this is the group of patients that might benefit from active surveillance. Our findings support the use of LUS and PFTs in the monitoring of children after COVID‐19 pneumonia with respiratory symptoms persisting beyond the acute infection.

AUTHOR CONTRIBUTIONS

Stanisław Bogusławski: Writing – original draft; investigation; conceptualization; methodology; writing – review and editing; formal analysis; project administration; data curation; supervision. Agnieszka Strzelak: Writing – original draft; methodology; validation; writing – review and editing; data curation; investigation; formal analysis; supervision; conceptualization. Kacper Gajko: Data curation; investigation. Joanna Peradzyńska: Formal analysis; writing – review and editing; data curation; methodology. Jolanta Popielska: Investigation; conceptualization. Magdalena Marczyńska: Investigation; conceptualization. Marek Kulus: Writing – review and editing. Katarzyna Krenke: Conceptualization; investigation; writing – original draft; methodology; writing – review and editing; formal analysis; project administration; data curation; supervision.

CONFLICT OF INTEREST

The authors declare no conflict of interest.

Bogusławski S, Strzelak A, Gajko K, et al. The outcomes of COVID‐19 pneumonia in children—clinical, radiographic, and pulmonary function assessment. Pediatr Pulmonol. 2022;1‐9. 10.1002/ppul.26291

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.