Discussion
The role of asthma as a risk factor for COVID-19 in children is
undetermined, and some authors highlight the need for more
data7. From the results of our series, we found that
11.1% of SARS-CoV-2 infected children suffer from asthma. This is
consistent with the global prevalence of asthma collected by the ISAAC
study1 from Europe and Spain, which is around 10.3%
in the pediatric population. Based on these observations, we could
consider that asthma is not a risk factor for SARS-CoV-2 infection in
children.
However, a higher percentage of asthma has been observed in children who
required admission or PICU (17.6% and 21.4% respectively), compared to
children with mild infection (6.7%), although the difference did not
reached statistical significance. We do not know if an increase in the
sample size could have yielded other results. These data should be taken
with caution since they have been obtained evaluating question 6 of the
ISAAC questionnaire that considers the diagnosis of asthma at any time
in the child’s life. However, when we analysed anti-asthmatic therapy in
the previous year, both the use of salbutamol and inhaled
corticosteroids were associated with increased risk of hospitalization,
up to 8 times higher for salbutamol (4 times in the PICU) and up to 2.9
for budesonide (12 times in the PICU). These data lead us to suggest
that active asthma could be a risk factor for more severe disease,
higher rates of hospitalization and of PICU admission due to COVID.
Our results are consistent with Floyd et al8 study
with more than 1000 children in Philadelphia, in which the authors did
not find asthma to be a risk factor for hospitalization. However, the
use of anti-asthmatic drugs was more frequent in hospitalized patients.
Floyd et al, extracted data from the medical records, an important
limitation of their study, while in our case the asthma diagnosis was
made using an internationally validated questionnaire and was obtained
directly from the parents, thereby reducing the bias of lack of data in
the medical records.
Our findings are also similar to a systematic review carried out by
Sunjaya et al9 in Australia, including 57 studies
(only 4 included children) with more than 300,000 confirmed SARS-CoV-2
infections. The prevalence of asthma in SARS-CoV-2 patients was similar
to the prevalence of global asthma (7.46%). Although the authors found
a higher percentage of asthmatics with severe COVID-19 and higher
requirement for ICU admission, the difference was not statistically
significant.
Recently, a cross-sectional study of 43 465 patients under 18 years of
age with COVID-19, has been published. More than 25% of patients had
one or more underlying condition. Asthma was found to be a risk factor
for hospitalization and clinical severity, although it is not specified
whether asthma was a current or previous condition 10.
Finally, Zu et al11, with a different approach,
performed a study analysing the genetic predisposition to allergic
asthma, employing data from the UK Biobank in 492,768 adult patients and
they found an association between non-allergic asthma and severe
COVID-19.
Despite our limitations, we conclude that a history of asthma was not a
risk factor for SARS-CoV-2 infection in our series, but active asthma
could be a risk factor for more severe evolution and need for
hospitalization for COVID-19 in children. More studies are needed to
clarify the role of asthma in pediatric population with COVID-19.
REFERENCES
- Arnedo A, Bellido JB, Pac MR, Artero A, Campos JB, Museros L,
Puig-Barberà J, Tosca R, Tornador E. Incidence of asthma and risk
factors in a cohort of schoolchildren aged from 6-7 years old to 14-15
years old in Castellón (Spain) following the International Study of
Asthma and Allergies in Childhood (ISAAC). Med Clin (Barc). 2007 Jun
30;129(5):165-70. Spanish. doi: 10.1157/13107792. PMID: 17669332.
- Caminati M, Lombardi C, Micheletto C, Roca E, Bigni B, Furci F,
Girelli D, Senna G, Crisafulli E. Asthmatic patients in COVID-19
outbreak: Few cases despite many cases. J Allergy Clin Immunol. 2020
Sep;146(3):541-542. doi: 10.1016/j.jaci.2020.05.049. Epub 2020 Jun 22.
PMID: 32620309; PMCID: PMC7306702.
- Izquierdo JL, Almonacid C, González Y, Del Rio-Bermudez C, Ancochea J,
Cárdenas R, Lumbreras S, Soriano JB. The impact of COVID-19 on
patients with asthma. Eur Respir J. 2021 Mar 4;57(3):2003142. doi:
10.1183/13993003.03142-2020. PMID: 33154029; PMCID: PMC7651839.
- Sisk B, Cull W, Harris JM, Rothenburger A, Olson L. National Trends of
Cases of COVID-19 in Children Based on US State Health Department
Data. Pediatrics. 2020 Dec;146(6):e2020027425. doi:
10.1542/peds.2020-027425. Epub 2020 Sep 29. PMID: 32994175.
- de Ceano-Vivas M, Martín-Espín I, Del Rosal T, Bueno-Barriocanal M,
Plata-Gallardo M, Ruiz-Domínguez JA, López-López R, Molina-Gutiérrez
MÁ, Bote-Gascón P, González-Bertolín I, García-Sánchez P,
Martín-Sánchez J, de Miguel-Lavisier B, Sainz T, Baquero-Artigao F,
Méndez-Echevarría A, Calvo C. SARS-CoV-2 infection in ambulatory and
hospitalised Spanish children. Arch Dis Child. 2020
Aug;105(8):808-809. doi: 10.1136/archdischild-2020-319366. Epub 2020
May 22. PMID: 32444450; PMCID: PMC7392480
- Dosanjh A. COVID 19 and Pediatric Asthma. J Asthma Allergy. 2020 Dec
2;13:647-648. doi: 10.2147/JAA.S291796. PMID: 33299331; PMCID:
PMC7720423.
- Castro-Rodriguez JA, Forno E. Asthma and COVID-19 in children: A
systematic review and call for data. Pediatr Pulmonol. 2020
Sep;55(9):2412-2418. doi: 10.1002/ppul.24909. Epub 2020 Jul 6. PMID:
32558360; PMCID: PMC7323291.
- Floyd GC, Dudley JW, Xiao R, Feudtner C, Taquechel K, Miller K,
Henrickson SE, Hill DA, Kenyon CC. Prevalence of asthma in
hospitalized and non-hospitalized children with COVID-19. J Allergy
Clin Immunol Pract. 2021 May;9(5):2077-2079.e2. doi:
10.1016/j.jaip.2021.02.038. Epub 2021 Mar 3. PMID: 33676051; PMCID:
PMC7927636.
- Sunjaya AP, Allida SM, Di Tanna GL, Jenkins C. Asthma and risk of
infection, hospitalization, ICU admission and mortality from COVID-19:
Systematic review and meta-analysis. J Asthma. 2021 Apr 1:1-14. doi:
10.1080/02770903.2021.1888116. Epub ahead of print. PMID: 33556287;
PMCID: PMC8022341.
- Kompaniyets L, Agathis NT, Nelson JM, Preston LE, Ko JY, Belay B,
Pennington AF, Danielson ML, DeSisto CL, Chevinsky JR, Schieber LZ,
Yusuf H, Baggs J, Mac Kenzie WR, Wong KK, Boehmer TK, Gundlapalli AV,
Goodman AB. Underlying Medical Conditions Associated With Severe
COVID-19 Illness Among Children. JAMA Netw Open. 2021 Jun
1;4(6):e2111182. doi: 10.1001/jamanetworkopen.2021.11182. PMID:
34097050; PMCID: PMC8185607.
- Zhu Z, Hasegawa K, Ma B, Fujiogi M, Camargo CA Jr, Liang L.
Association of asthma and its genetic predisposition with the risk of
severe COVID-19. J Allergy Clin Immunol. 2020 Aug;146(2):327-329.e4.
doi: 10.1016/j.jaci.2020.06.001. Epub 2020 Jun 6. PMID: 32522462;
PMCID: PMC7423602.