Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about bronchialitis.

And if you want to follow along with written notes on this topic,

you can follow along at zero definals.com slash bronchialitis or in the respiratory section

of the Zero to Finals Pediatrics book. So let's get straight

into it. Bronchiolitis describes inflammation and infection in the bronchioles, which are the small

airways in the lungs. This is usually caused by a virus and respiratory syncytial virus or RSV is the most common cause.

Bronchiolitis is very common in winter.

Bronchiolitis is generally considered to occur in infants under one years of age,

although it's most common in infants under six months.

It can rarely be diagnosed in children up to two years of age,

particularly in ex-premature babies who have chronic lung disease.

When a virus affects the airways in adults, the swelling and the mucus inside the airways

is proportionately so small it has a little noticeable effect on the breathing.

The airways in infants are very small to begin with,

and when there's even the slightest amount of inflammation and mucus in the airway,

it has a significant effect on their ability to circulate air in the alveoli and back out again.

So this causes harsh breast sounds, whee's and crackles that are heard

when you osculate the chest in a bronchiolitic infant. Essentially a small amount of inflammation and

mucus collects in tiny, tiny bronchials and this causes an obstruction to airflow in and out of the chest. So how does it present?

Corrhizal symptoms are the typical symptoms of a viral upper respiratory tract infection with a runny

or snotty nose, sneezing, mucus in the throat and watery eyes. And this is what we describe as

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