Croup is a very common, albeit distressing condition of childhood, usually occurring within the first 6 years of life. The highest incidence is seen at 24 months. It is most commonly due to a viral infection of the throat and the trachea. This leads to a swelling of the mucous membrane that lines the airway.
Since small children already have a narrow airway (as compared to adults), even a little swelling produces a drastic narrowing of the airway. This leads to the characteristic inspiratory stridor, or high-pitched sound produced when air is drawn in, as well as a barking cough.
Croup is caused by viruses such as the parainfluenza virus (most commonly), the adenoviruses, respiratory syncytial virus (RSV), or the measles virus. These are usually transferred by hand-to-surface contact.
Croup is essentially a clinical diagnosis. It is made on the basis of the symptoms of hoarseness, a very characteristic barking cough, and respiratory difficulties (following a slight cold during the preceding days). The symptoms are typically much worse during the night, perhaps because the cold of the night air further inflames the respiratory lining mucous membrane.
The physical examination may show inspiratory stridor, retraction of the intercostal muscles with breathing, as well as various signs of respiratory difficulty on auscultation. These may include wheezing and reduced breath sounds.
There is usually no need for specific laboratory and imaging testing, but these may be employed to exclude other diseases in certain patients with a severe or atypical clinical presentation. Even though chest radiography cannot be used to diagnose croup, it can help to rule out some other pulmonary conditions when we are not sure of the diagnosis in a child presenting with inspiratory stridor.
Croup can usually be treated at home. However, you should always carry out home care under the guidance of your health care provider- even if you do not plan to take your child to the hospital.
It is important to keep the child calm. This may be accomplished with the help of familiar and beloved security objects, by holding or rocking the child, and always speaking and looking serene, even if the caregiver is afraid the condition is worsening. This is because children can sense anxiety and become fearful, which in turn increases the airway constriction and worsens the symptoms of respiratory distress.
The child should be given drinks in small quantities very frequently, as the rapid shallow breathing causes the loss of much water vapor from the lungs, potentially leading to dehydration.
Acetaminophen may be given to settle fever or sore throat symptoms under the doctor’s advice. The lowering of temperature will also reduce the respiratory rate and so decrease the work of respiration. The healthcare provider may prescribe a steroid which will reduce the degree of airway swelling. This will provide symptomatic relief and also often prevent the need for hospital admission.
Parents often claim some benefit from keeping the child in a moist environment such as the steamed-up bathroom, or with a cool air vaporizer in the bedroom, even though concrete medical evidence is lacking. Burns and scalds sometimes occur with the use of steam; therefore extreme caution is required, especially since hard proof of its effectiveness is lacking. Sometimes going out into the cool night air is soothing to the inflamed airways.
If the symptoms become worse, the child should be under medical care as:
- Breathing may stop altogether in severe cases of croup
- The diagnosis may not be croup but something more serious.
The following signs indicate that the child requires hospital treatment:
- The child has a high temperature
- The child doesn’t look well or act normal, but looks anxious, sweats profusely, or is tired out with the effort of breathing
- Cyanosis (i.e. the appearance of a bluish tinge around the mouth, the lips, or the nails) has developed, reflecting seriously impaired oxygenation of the blood due to reduced airflow through the lungs
- The breathing rate has gone up drastically as the body attempts to compensate for the shallow breathing
- The child is struggling for breath
- The child’s breathing is noisy both during inspiration and expiration, because of the reduced space for airflow inside the extremely narrowed airway
- The child develops drooling or difficulty with swallowing
- The child develops a cough of acute onset
- The child is dehydrated because of inability to drink fluids
Hospital treatment for croup includes the following measures:
- Nebulized epinephrine helps to relieve airway obstruction by reducing the mucous membrane swelling quickly, usually within a half-hour. The effect is short-lived, waning in a couple of hours at most, but without rebound phenomenon.
- Oral, inhaled or injected glucocorticoids (such as budesonide or dexamethasone) help to maintain the reduction in mucous membrane swelling for a long period after each dose, up to 72 hours. They are the first choice in most cases of croup which require treatment. Systemic steroids may not be useful as first-line treatment in severe croup because they take up to 1-6 hours to act. Inhaled budesonide acts more rapidly, within about 30 minutes. The widespread use of steroids in the treatment of croup has brought down the hospital admission rate by almost a third.
- Antibiotics may be given in case secondary infection is present or likely to occur.
- An oxygen tent will provide a higher concentration of inhaled oxygen and so bring down the respiratory rate and ease breathing.
- Fluids may be given intravenously if the child is dehydrated.
In most cases, the child does not require admission but may be discharged home after treatment in the emergency room.
Reviewed by: Dr Tomislav Meštrović, MD, PhD