INTRODUCTION
The domestic cats (Felis catus) have long been known to be one of the
most common respiratory allergens.1 Cat sensitivity
rates vary between 20% and 50% in previous
studies.2,3 Cat allergen is the second most frequent
indoor allergen and the third most common among all aeroallergens after
pollens and house dust mites.4 More than 350,000
emergency room visits occur due to cat allergy-related asthma attacks in
the USA every year.5
Cat sensitization seems to be one of the most important risk factors for
both the development of asthma and the rising frequency of asthma
attacks.5,6,7 However, there are also some
contradictory findings in the literature suggesting that cat
sensitization may increase respiratory symptoms a non-linear manner with
exposure or that intense exposure to cats at early ages may be even
protective.8-12 Recent studies have shown that asthma
severity, the frequency of wheezy attacks, medication requirements, and
unpredictable physician visits due to allergic respiratory symptoms
resulting from cat allergen exposure increase with cat sensitivity in
children.13-16
Although conventional spirometry is a highly valuable test for detecting
airway obstruction and diagnosing asthma, it is also subject to a number
of limitations. Being effort-dependent and requiring high cooperation,
it is difficult for children, particularly those of preschool-age. In
addition, it does not provide sufficient information about peripheral
airways.17 Impulse oscillometry (IOS) is a
standardized, non-invasive, practical alternative test that requires
less effort than spirometry. It is very useful for measuring entire and
peripheral respiratory functions, particularly in preschool-age children
unable to adapt to spirometry. IOS also provides important data
regarding the deterioration in airway function that may develop in
children with respiratory allergic diseases at early ages, and also
yields more specific data about lung resistance, reactance, and
peripheral airway obstruction.18,19
This study was set out to evaluate the respiratory function tests of
children with cat sensitization and respiratory allergic diseases
(asthma and/or allergic rhinitis) using IOS and spirometry,
respectively, and to compare the resulting data with those of healthy
controls, and also to evaluate the potential risk factors that may
affect lung functions.