Title:Why do some Children Get Sick with Recurrent Respiratory Infections?
Volume: 20
Issue: 3
Author(s): Fabio Cardinale, Francesco La Torre, Lucia Grazia Tricarico, Giuseppe Verriello and Carla Mastrorilli*
Affiliation:
- Pediatric and Emergency Unit, AOU Consorziale Policlinic of Bari, Giovanni XXIII Pediatric Hospital, Bari, Italy
Keywords:
Atopy, children, environmental factors, genetics, obesity, pathogenesis, pediatric, recurrent respiratory infections, respiratory microbiota, vitamin D.
Abstract: Respiratory tract infections (RTI) represent a frequent condition, particularly among
preschool children, with an important burden on the affected children and their families. It has
been estimated that recurrent RTIs affect up to 25% of children during the first 4 years of life. These
infections are mainly caused by viruses and are generally self-limiting. Social and environmental
factors have been studied in determining the incidence of recurrent RTIs and the mostly recognized
are precocious day care attendance, tobacco exposure and pollution. Primary immune defects,
local anatomical factors, and genetic disorders such as primary ciliary dyskinesia or cystic fibrosis,
may be also involved in recurrent RTIs of a subgroup of children, typically characterized by
more severe and chronic symptoms. However, there is increasing awareness that RTIs have a complex
pathophysiology and that some underrecognized factors, including genetic susceptibility to infections,
low levels of some micronutrients, and respiratory microbiota might shape the probability
for the child to develop RTIs. The sum (i.e. the number) of these factors may help in explaining
why some children get sick for RTIs whilst other not. In some children iatrogenic factors, including
improper use of antibiotics and NSAIDS or glucocorticoids might also aggravate this condition,
further weakening the host's immune response and the possibly of establishing a “vicious circle”.
The present review aims to focus on several possible factors involved in influencing RTIs and
to propose a unifying hypothesis on pathophysiological mechanisms of unexplained recurrent RTIs
in children.
