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  • Dr Nitin Shastri, Consultant Paediatrician

What Is Croup & Who Is Most at Risk?

Croup is most commonly the result of an infectious respiratory illness. It causes a change in breathing causing a brassy, barking cough. Children are most at risk of croup from around 4 months of age (when the natural immunity received from their Mother starts to decline) until around 3 years old (when their airway is considerably larger).

Can age make a difference?

The size of a child’s airway is roughly proportional to their height. From birth to adulthood, a child’s height will typically increase by a factor of 3 to 4, and so will the size of their airway.

A reduction in the radius of an infant’s airway can cause resistance in their breathing. The two are very sensitively linked. Croup can cause the airway to become inflamed (swelling), which increases the resistance of the infant’s airway and their ability to breathe with ease. However, this may only cause minor discomfort for an older child.

Infectious Croup vs Spasmodic Croup – what’s the difference?

Croup can be broadly divided into two categories: Infectious Croup and Spasmodic Croup.

(1) Infectious Croup

Most cases of croup are caused by a virus. The virus usually enters through a child’s upper airways. The first symptoms will be those of a cold; a congested, runny nose, a low-grade fever or a mild sore throat.

As the virus travels further down the throat, the linings of the voice box and windpipe become red, swollen, narrow and irritated - triggering hoarseness, a barking cough and loud, raspy breathing (stridor). The symptoms from infectious croup usually resolve over 3 to 5 days.

(2) Spasmodic Croup

Spasmodic Croup can be triggered by an infection, but it isn’t caused by infection. It tends to run in families and may be caused by an allergic reaction. Spasmodic Croup tends to come on suddenly without fever.

Episodes of cough and loud raspy breathing usually start without warning, often in the middle of the night. Symptoms typically improve within a few hours, though typically reappear several nights in a row. The period between such episodes can vary.

Signs and Symptoms:

Most children with croup are mildly ill, and do not develop significant breathing problems. Symptoms of more severe illness include:

  • Breathing faster than normal

  • Having difficulty breathing and feeding

  • Flaring nostrils

  • Recessions - grooves between the ribs or between the ribs and the tummy

  • Unusual agitation

Most children with croup can be safely managed on an outpatient basis, but some children will require hospital admission.

When should I call my child’s doctor?

Contact your child’s doctor if the croup prevents your child speaking. If your child is dribbling or drooling or has a high persistent fever, then this is a sign of a possibly more a serious infection. As croup looks so dramatic, especially when it happens for the first time, and usually in the middle of the night, the best immediate course of action is to call an ambulance. There are several relatively simple treatments which can be used to help croup, and with confidence parents can possibly give these treatments at home. However, the safety of the child is of the greatest importance, so always call an ambulance if you are worried.

For more information on the diagnosis and treatment of Croup please click here. (link to our previous article)

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