Asthma

Asthma in children

1. Asthma triggers include smoke, perfume, pollen, mold, dust mites, and viral infections.
2. Wheezing, cough, shortness of breath, chest tightness, and difficulty breathing are symptoms of asthma.
3. The diagnosis is based on a child's repeated wheezing episodes and a family history of asthma.
4. Most children with asthma outgrow the disorder.
5. Asthma can be prevented by avoiding triggers.
6. Treatment includes bronchodilators and inhaled corticosteroids.

Although asthma can develop at any age, it most commonly begins in children, particularly in the first 5 years of life. Some children continue to have asthma into the adult years. In other children, asthma resolves. Asthma has become much more common in recent decades, increase in recent decades. The rate soars to 25% to 40% among some populations of urban children. Asthma is the leading cause of hospitalization for children and is the number one chronic condition causing elementary school absenteeism. Most children with asthma are able to participate in normal childhood activities, except during flare-ups. A smaller number of children have moderate or severe asthma and need to take daily preventive drugs to enable them to engage in sports and normal play. For unknown reasons, children with asthma respond to certain stimuli (triggers) in ways that children without asthma do not. There are many potential triggers, and most children respond to only a few. In some children, specific triggers for flare-ups cannot be identified.

These triggers all result in a similar response. Certain cells in the airways release chemical substances. These substances cause the airways to become inflamed and swollen and stimulate the muscle cells in the walls of the airways to contract. Repeated stimulation by these chemical substances increases mucus production in the airways, causes shedding of the cells lining the airways, and enlarges the muscle cells in the walls of the airways. Each of these responses contributes to a sudden narrowing of the airways (asthma attack). In most children, the airways return to normal between asthma attacks.

Common Asthma Triggers

Risk Factors

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 are 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 and low birth weight is also risk factors.
• 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
• Children who are exposed to high concentrations of allergens, such as dust mites or cockroach feces, at an early age are more likely to develop asthma.
• Children who have bronchiolitis 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

Symptoms

• As the airways narrow in an asthma attack, the child develops difficulty breathing, chest tightness and coughing, typically accompanied by wheezing.
• Wheezing 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 extremely severe asthma may not wheeze because there is too little air flowing 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 with frequent severe attacks sometimes have a slowing of their growth, but their growth usually catches up to that of other children by adulthood.

Diagnosis

• A doctor suspects asthma in children who have repeated episodes of wheezing, particularly when family members are known to have asthma or allergies
• Doctors usually order x-rays, and they sometimes do allergy testing to help determine causes.
• Children with frequent wheezing may be tested for other disorders, such as cystic fibrosis or gastroesophageal reflux.
• Older children sometimes undergo pulmonary function tests (PFT)), although in most children, pulmonary function is normal between flare-ups.
• Older children or adolescents known to have asthma often use a peak flow meter (a small device that records how fast a person can blow out air) to measure the degree of airway obstruction. 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.

Prevention

• One half or more of children with asthma outgrow the condition. Those with more severe disease are more likely to have asthma as adults. Other risk factors for persistence and relapse include female sex, smoking, developing asthma at a younger age, and sensitivity to household dust mites.
• Asthma flare-ups often can be prevented by avoiding whatever triggers a particular child's attacks. Parents of children with allergies usually are advised to remove feather pillows, carpets, drapes, upholstered furniture, stuffed toys, and other potential sources of dust mites and allergens from the child's room.
• Passive Cigarette smoke often worsens symptoms in children with asthma, so it is important to eliminate smoking in areas where the child spends time.
• If a particular allergen cannot be avoided, a doctor may try to desensitize the child by using allergy shots, although the benefits of allergy shots for asthma are not well known.
• 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

Treatment of an acute attack consists of

Opening the airways (bronchodilation) and stopping inflammation

• A variety of inhaled drugs open the airways. Older children and adolescents usually can take drugs using a metered-dose inhaler. Children younger than 8 years or so often find it easier to use an inhaler with a spacer or holding chamber attached.
• Infants and very young children sometimes can use an inhaler and spacer if an infant-sized mask is attached. Those who cannot use inhalers may receive inhaled drugs at home through a mask connected to a nebulizer, a small device that creates a mist of the drug by using compressed air. Inhalers and nebulizers are equally effective at delivering the drug also can be taken by mouth, although this route is less effective than inhalation and usually is used only in infants who do not have a nebulizer. Children with moderately severe attacks also may be given corticosteroids by mouth.
• Children with very severe attacks are treated in the hospital with bronchodilators given in a nebulizer or an inhaler at least every 20 minutes initially. Sometimes doctors use injections of epinephrine (a bronchodilator) in children with very severe attacks if inhaled drugs are not effective. Doctors usually give corticosteroids by vein to children having a severe attack.
• Children who have mild, infrequent attacks usually take drugs only during an attack. Children with 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 use a low dose of an inhaled corticosteroid every day to help prevent attacks. These drugs reduce inflammation by blocking the release of the chemical substances that inflame the airways.
• Drugs are increased or decreased over time to achieve optimal control of the child's asthma symptoms and prevent severe attacks. If these drugs do not prevent severe attacks, children may need to take corticosteroids by mouth. Children who experience attacks during exercise usually inhale a dose of bronchodilator just before exercising.
• Because asthma is a long-term condition with a variety of treatments, doctors work with parents and children to make sure they understand the condition as well as possible.
• Parents and doctors should inform school teachers and others about the child's condition and the drugs being used. Some children may be permitted to use inhalers in school as needed, and others must be supervised by the school doctor.