Asthma in Children

Doctors do not completely understand why some children develop asthma, but a number of risk factors are recognized:

A child with one parent who has asthma has a 25% risk of developing asthma. If both parents have asthma, the risk increases to 50%. Children whose mothers smoked during pregnancy may be more likely to develop asthma. Asthma also has been linked to other factors related to the mother, such as young maternal age, poor maternal nutrition, and lack of breastfeeding. Prematurity Preterm (Premature) Newborns A preterm newborn is a baby delivered before 37 weeks of gestation. Depending on when they are born, preterm newborns have underdeveloped organs, which may not be ready to function outside of... read more and low birth weight are also risk factors.

In the United States, children in urban environments are more likely to develop asthma, particularly if they are from lower socioeconomic groups. Although it is not entirely understood, it is believed that poorer living conditions, greater potential exposure to triggers, and less access to health care contribute to the higher incidence of asthma in these groups. Although asthma affects a higher percentage of Black children than White children, the role that genetic aspects of race play in the increasing rate of asthma is controversial because Black children are also more likely to live in urban areas.

Children who are exposed to high concentrations of certain allergens, such as dust mites or cockroach feces, at an early age are more likely to develop asthma. However, doctors have noticed that asthma is more common among children living in very clean, hygienic environments where they are exposed to fewer infectious diseases than children living in environments where they are exposed to more infectious diseases. Thus, doctors think that perhaps childhood exposure to certain substances and infections may actually help children's immune system learn not to overreact to triggers.

Most children who are having an asthma attack and 90% of children who have been hospitalized for asthma have a viral infection (usually rhinovirus or the common cold Common Cold The common cold is a viral infection of the lining of the nose, sinuses, and throat. Many different viruses cause colds. Usually, colds are spread when a person's hands come in contact with... read more ). Children who have bronchiolitis Bronchiolitis Bronchiolitis is a viral infection that affects the lower respiratory tract of infants and young children under 24 months of age. Bronchiolitis usually is caused by viruses. Symptoms include... read more at an early age often wheeze with subsequent viral infections. The wheezing may at first be interpreted as asthma, but these children are no more likely than others to have asthma during adolescence.

Diet may be a risk factor. Children who do not consume enough of vitamins C and E and omega-3 fatty acids or who are obese may be at higher risk of asthma.

As the airways narrow in an asthma attack, the child develops difficulty breathing, chest tightness, and 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 , typically accompanied by wheezing. Wheezing Wheezing in Infants and Young Children Wheezing is a relatively high-pitched whistling sound that occurs during breathing when the airways are partially blocked or narrowed. Wheezing is caused by a narrowing of the airways. Other... read more is a high-pitched noise heard when the child breathes out.

Not all asthma attacks cause wheezing, however. Mild asthma, particularly in very young children, may result only in a cough. Some older children with mild asthma tend to cough only when exercising or when exposed to cold air. Also, children with an extremely severe asthma attack may actually not wheeze because there is too little air flowing even to make a noise.

In a severe attack, breathing becomes visibly difficult, wheezing usually becomes louder, the child breathes faster and with greater effort, and the ribs stand out when the child breathes in (inspiration). With very severe attacks, the child gasps for breath and sits upright, leaning forward. The skin is sweaty and pale or blue-tinged. Children who have frequent severe attacks sometimes have slowed growth, but their growth usually is similar to that of other children by adulthood.

A doctor suspects asthma in children who have repeated episodes of wheezing, particularly when family members are known to have asthma or allergies. However, asthma is only one of several causes of wheezing Causes Wheezing is a relatively high-pitched whistling sound that occurs during breathing when the airways are partially blocked or narrowed. Wheezing is caused by a narrowing of the airways. Other... read more . X-rays of the chest are rarely necessary for the diagnosis of asthma in children. X-rays are usually done only if doctors think that the child's symptoms might be caused by a different disorder, such as pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more . Doctors sometimes do allergy testing Allergy testing Seasonal allergies result from exposure to airborne substances (such as pollens) that appear only during certain times of the year. Seasonal allergies cause itchy skin, a runny nose, sneezing... read more to help determine potential triggers.

Children with frequent wheezing episodes may be tested for other disorders, such as cystic fibrosis Diagnosis Cystic fibrosis is a hereditary disease that causes certain glands to produce abnormally thick secretions, resulting in tissue and organ damage, especially in the lungs and the digestive tract... read more or gastroesophageal reflux Diagnosis Gastroesophageal reflux is the backward movement of food and acid from the stomach into the esophagus and sometimes into the mouth. Reflux may be caused by the infant’s position during feeding... read more . Older children sometimes undergo tests that are used to measure how well the lungs function (pulmonary function tests Pulmonary Function Testing (PFT) Pulmonary function tests measure the lungs' capacity to hold air, to move air in and out, and to absorb oxygen. Pulmonary function tests are better at detecting the general type and severity... read more ). In most children with asthma, lung function is normal between flare-ups.

Older children or adolescents known to have asthma often use a peak flow meter (a small handheld device that records how fast a person can blow out air) to measure the degree of airway narrowing. This device can be used at home. Doctors and parents can use this measurement to assess the child's condition during an attack and between attacks. X-rays are not done during an attack in children known to have asthma unless doctors suspect another disorder such as pneumonia or a collapsed lung.

Many children outgrow asthma. However, as many as 1 in 4 children either continue to have asthma attacks or the asthma symptoms resolve only to return (called relapse) when children are older. Children who have severe asthma are more likely to have asthma as adults. Other risk factors for persistence and relapse include female sex, smoking, development of asthma at a younger age, and sensitivity to household dust mites.

Although asthma causes a significant number of deaths each year, most of these are preventable with treatment. Thus, the prognosis is good for children who have access to treatment and who are able to follow their treatment plan.

It is not yet known how to prevent a child with a family history of asthma from developing asthma. However, there is evidence that children of mothers who smoked during pregnancy are more likely to have asthma. Thus, pregnant women should not smoke, especially if there is a family history of asthma.

On the other hand, there are many things that can be done to prevent asthma symptoms or attacks in children who have asthma.

Asthma flare-ups often can be prevented by avoiding or trying to control whatever triggers a particular child's attacks. Children who have allergies should have the following items removed from their bedroom:

Other ways to reduce allergens include

Secondhand tobacco smoke often worsens symptoms in children with asthma, so it is important to eliminate smoking at least in areas where the child spends time.

Other triggers, such as strong odors, irritating fumes, cold temperatures, and high humidity, should also be avoided or controlled when possible.

Because exercise is so important for a child's development, doctors usually encourage children to maintain physical activities, exercise, and sports participation and use an asthma drug immediately before exercising if needed.

Treatment is given to resolve sudden (acute) attacks and sometimes to prevent attacks.

Children who have mild, very infrequent attacks usually take drugs only during an attack. Children who have more frequent or severe attacks also need to take drugs even when they are not having attacks. Different drugs are used depending on the frequency and severity of the attacks. Children with infrequent attacks that are not very severe usually take a low dose of an inhaled corticosteroid or a leukotriene modifier (montelukast or zafirlukast) every day to help prevent attacks. These drugs reduce inflammation by blocking the release of the chemical substances that inflame the airways.