Croup primarily affects children 6 months to 3 years of age.
Most children have only a single episode of croup, but a few have repeated episodes (called spasmodic croup), initiated by viral infections, that gradually decrease in frequency and severity. Allergies or airway reactivity (such as occurs in asthma Asthma in Children Asthma is a recurring inflammatory lung disorder in which certain stimuli (triggers) inflame the airways and cause them to temporarily narrow, resulting in difficulty breathing. Asthma triggers... read more ) may play a role in spasmodic croup.
Croup is caused by a viral infection that leads to swelling of the lining of the airways, particularly the area just below the voice box (larynx).
The most common cause of croup is
Croup can also be caused by other viruses, such as respiratory syncytial virus Respiratory Syncytial Virus (RSV) Infection and Human Metapneumovirus Infection Respiratory syncytial virus infection and human metapneumovirus infection cause upper and sometimes lower respiratory tract infections. Respiratory syncytial virus is a very common cause of... read more (RSV) or an influenza virus Influenza (Flu) Influenza (flu) is a viral infection of the lungs and airways with one of the influenza viruses. It causes a fever, runny nose, sore throat, cough, headache, muscle aches (myalgias), and a general... read more . Croup caused by an influenza virus may be particularly severe and may occur in a broader age range of children.
Although croup occurs throughout the year, seasonal outbreaks are common. Croup caused by parainfluenza viruses tends to occur in the fall, and croup caused by RSV and influenza viruses tends to occur in the winter and spring. The infection usually is spread by breathing in airborne droplets containing viruses or by having contact with objects contaminated by these droplets.
Croup usually starts with symptoms of a cold—runny nose, sneezing, mild fever Fever in Infants and Children Normal body temperature varies from person to person and throughout the day (it is typically highest in the afternoon). Normal body temperature is higher in preschool-aged children and highest... read more , and some coughing Cough in Children Cough helps clear materials from the airways and prevent them from going to the lungs. The materials may be particles that have been inhaled or substances from the lungs and/or airways. Most... read more . Then the child develops hoarseness and a frequent, unusual-sounding cough, which is described as brassy or barking. Croup ranges widely in its severity. Sometimes swelling of the airway causes difficulty breathing, which is most noticeable when breathing in (inspiration). In severe croup, there may be a loud squeaking noise (stridor Stridor Stridor is a gasping sound during inhalation resulting from a partial blockage of the throat (pharynx), voice box (larynx), or windpipe (trachea). Stridor is usually loud enough to be heard... read more ) heard with each inspiration. About 50% of children have a fever. All symptoms are typically much worse at night and may awaken children from sleep. Symptoms often seem to lessen in the morning and worsen again the next night.
The worst of the symptoms usually lasts 3 to 4 days, and the cough continues but changes to a looser-sounding cough. This change can cause concern for parents who think the infection has moved to the chest. However, it is the normal progression of the illness.
A doctor distinguishes croup by its characteristic symptoms, especially the sound of the cough.
X-rays Plain X-Rays X-rays are high-energy radiation waves that can penetrate most substances (to varying degrees). In very low doses, x-rays are used to produce images that help doctors diagnose disease. In high... read more of the neck and chest help the doctor make a definitive diagnosis of croup.
If a child develops a croupy breathing pattern, the parents should contact the doctor because children with croup can become very ill very quickly.
Mildly ill children may be cared for at home and usually recover in 3 to 4 days. The child should be made comfortable, given plenty of fluids, and allowed to rest because fatigue and crying can worsen the condition. Home humidifying devices (for example, cool-mist vaporizers or humidifiers) may reduce drying of the upper airways and ease breathing. The humidity can be raised quickly by running a hot shower to steam up the bathroom. Carrying the child outside to breathe cold night air or to the kitchen to breathe cold air from the freezer also may open the airways. Although these remedies are harmless, there is little scientific evidence that they make any difference in how children feel.
For sicker children, the doctor may recommend a single dose of a corticosteroid to prevent worsening of symptoms. Children with worsening symptoms should be seen immediately by a doctor who will likely recommend corticosteroids and may hospitalize the child for observation and care.
Children who have increasing or continuing difficulty in breathing, rapid heart rate, fatigue, dehydration, or bluish skin discoloration need to be given oxygen, as well as fluids by vein. Doctors usually treat children with epinephrine given in a nebulizer and corticosteroids given by mouth or injection. These drugs help shrink swollen tissue in the airways. Children who improve with these treatments may be sent home, but children who are very ill should remain in the hospital.
Antibiotics are used only in the rare situation when a child with croup also develops a bacterial infection. Rarely, a ventilator Mechanical Ventilation Mechanical ventilation is use of a machine to aid the movement of air into and out of the lungs. Some people with respiratory failure need a mechanical ventilator (a machine that helps air get... read more (a breathing machine that helps air get in and out of the lungs) is needed.