Croup: Basics, symptoms and treatment

What is croup?

Croup is almost always a viral infection of the voice box (larynx) and windpipe (trachea) associated with signs of a respiratory infection, such as a runny nose or cough. It is a very common childhood ailment.

Usually the first indication is a cough that sounds like the bark of a dog or seal. Your child may have trouble breathing because the tissue around the larynx is inflamed, constricting the windpipe, and because the bronchial passages are blocked with mucus. The sound of air being forced through the narrowed airways may produce a hollow, raspy noise, called stridor, with each inhaled breath. However, there tends to be no similar sound with exhalation, as in wheezing.

Croup usually lasts for five or six days and is highly contagious to other children who have not had the disease. It usually affects children between the ages of six months and three years, whose small windpipes and bronchial passages are most vulnerable to blockage.  Children over six can get croup, though it is unusual.  It is rare in babies under six months.

Many cases are mild and can be managed at home.  It is important not to check your child’s throat by inserting an object. This can trigger spasm in the airway. In severe cases or in the case of epiglottitis -- an unrelated bacterial infection of the epiglottis (the tissue flap that covers the trachea when swallowing), the symptoms of which can sometimes mimic croup in early stages -- your child may need to be hospitalised, so do call for help from NHS Direct, your GP or the ambulance service.

Epiglottitis is distinguished from croup by drooling, refusal to swallow, and a more ill appearing child who is most comfortable sitting up and leaning forward. Other critical signs to look for are:

• Lips or face turning blue
• Increasing drowsiness/tiredness
• Difficulty breathing
• Any steady or sudden deterioration
• A high fever and/or a fast heart beat
• Collapse or near collapse.

If any of these symptoms are present, always consider calling 999.  This disease is now very rare because there is an immunisation against the most common bacteria causing this infection.

What causes croup?

Most croup cases are caused by a parainfluenza virus. The disease is transmitted by airborne droplets from an infected child's cough.

What are the symptoms of croup?

• A sharp, barking cough, usually accompanied by noisy and difficult breathing, and sometimes by hoarseness caused by inflamed vocal cords (laryngitis).
• Laboured breathing that seems to put strain on the neck muscles, ribs, or breastbone, consequently making these areas contract noticeably with each breath.