▴ 그림 6~8. 천식 발작이 유발됐을 때 기도의 변화와 기도의 횡단 그림
a-정상 기도(기관지),
b-급성 기관지 수축,
c-만성 천식으로 기도가 수축되고 기관지 벽에 염증이 생 겨 기도가 더 좁아진 것,
d-아 급성 천식이나 만성 천식으로 기관지 벽이 붓고 거기에 염증이 생겨 기도가 더 좁아졌다.
e-염증성 세포,
m-비만세포에서 히스타민 과립체가 분비된다.
T 세포,
B 세포,
p 폐포 대식 세포,
o 호산구, 호중구 등이 활성화되어 생긴 히스타민, 사이토카인, 류코트리엔, 프로스타글란딘 등 여러 가지 매개체가 생겨 그것들이 복합적으로 작용해 천식이 발작될 수 있다.
MBP; 주요 호염기구 세포독성 효소(호염기구/Major basophilic protein)가 분비되고
PAF:혈소판활성화 인자(Platelet activating factor/PAF)
참조문헌-Asthma, The Pediatric Clinics of North America, December 1992, W. B. Saunders
Copyright drleepediatrics.com 2/22/2026
Asthma (Bronchial Asthma)
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■ Overview of Asthma (Bronchial Asthma)
● “The airway is the passageway through which air flows into and out of the lungs.”
● The airway encompasses the respiratory system, starting from the nostrils and extending to the nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles.
● Strictly speaking, the oral cavity can also be considered an airway, but it is part of the digestive system.
● Asthma is a chronic inflammatory disease of the airway. It is also defined as a variable disease and is a type of inherited respiratory disease.
■ When the airways (airways) are exposed to external or internal triggers, lesions (1-4) develop in the airways, and the symptoms and signs associated with them occur in common, it is considered asthma.
● The bronchi become sensitive to various triggers,
● The bronchi constrict and narrow,
● The bronchi become inflamed,
● The bronchial walls swell,
● Phlegm production,
● Coughing and/or shortness of breath may occur.
■ Incidence and Epidemiology of Asthma (Bronchial Asthma)
● Asthma can affect anyone, regardless of age, including newborns, infants, toddlers, preschoolers, school-aged children, adolescents, and adults. ● Asthma affects 5% of Americans of all ages,
● Asthma affects 8-12% of all Americans,
● Asthma affects 5-7% of American children,
● Asthma affects 10-15% of American boys and 7-10% of American girls.
● Asthma affects 40% of children with allergic rhinitis.
● Up to 90% of children with a history of asthma may develop allergic rhinitis, and in general, when allergic rhinitis and asthma coexist, treating the allergic rhinitis can also treat the asthma, so they are closely related.
● 30% of children with a history of asthma experience their first asthma attack before their first birthday,
● 80-90% of children with a history of asthma begin to experience asthma attacks before the age of 4-5.
● The majority of childhood asthma is intermittent asthma. Most children with intermittent asthma are successfully treated, but in rare cases, persistent asthma attacks occur.
● Some doctors claim that 50% of children with asthma stop having asthma attacks 10 to 20 years after the onset of their condition, but asthma is a hereditary airway disease that cannot be completely cured.
● It is a disease of the airway variability, meaning that exposure to asthma triggers at any time throughout life can trigger another asthma attack.
● Asthma is the most common chronic respiratory disease seen in children.
■ According to asthma (bronchial asthma) statistics,
● 14.5 million people in the United States receive hospital treatment for asthma annually.
● Of these, 450,000 are hospitalized, and 1-2 million receive emergency treatment.
● 10 million elementary, middle, and high school students miss school due to asthma.
● 5,000 people die annually due to asthma.
● In 2006, asthma treatment costs in the United States reached $1.97 billion.
● In 2006, approximately 22 million Americans suffered from asthma.
● Of the 22 million Americans with asthma in 2006, 6.8 million were children and adolescents under the age of 18.
▴ Figure 158. Asthma prevalence in American children aged 0-17.
National Health Interview Survey, Pediatric News. May 2005
▴ Figure 159. Incidence of childhood asthma.
National Health Interview Survey, Pediatric News. May 2005
■ Instead of the medical name “asthma (bronchial asthma),” the following terms are sometimes used:
● Bronchial asthma
● Asthma
● Asthmatic bronchitis
● Reactive airway disease
● Irritable airway disease
● Wheezy child
● Chronic bronchitis
● Wheezy bronchitis
● Viral-associated wheezing
● Asthma in children is called “childhood asthma.”
● Atopic-related asthma
● Allergy-related asthma
● Other names are also used.
When the bronchial tubes come into contact with triggers for an asthma attack (bronchial asthma),
● the smooth muscles of the bronchial walls contract,
● inflammation and edema occur in the bronchial walls,
● mucus is secreted from the mucosal layer of the bronchial walls into the bronchial tubes,
● resulting in lesions that narrow the bronchial airways.
● The extent of bronchial lesions varies depending on the type, severity, and age of asthma.
● These lesions can naturally and temporarily resolve, and with appropriate treatment, the airways typically return to normal.
● Without appropriate treatment, bronchial damage caused by asthma can persist for life.
● When an asthma attack is triggered, lesions may occur only in the bronchial tubes,
● lesions similar to those in the bronchial tubes may occur only in the larynx,
● lesions may occur only in the trachea,
● lesions may occur only in the bronchial tubes and bronchioles,
● lesions may occur only in the bronchioles,
● lesions may occur only in the bronchioles,
● lesions may occur throughout the lower respiratory tract, including the larynx, trachea, bronchial tubes, and bronchioles.
■ Asthma (Bronchoalveolar Asthma) Attack Mechanism as Seen in Pictures (Figures 1-8)
Asthma (Bronchoalveolar Asthma) Attack Mechanism (Figures 1-8) When the airways are exposed to external or internal triggers, lesions (1-8) develop in the airways, and the accompanying symptoms and signs occur in common, it is considered asthma.
● The mechanism by which asthma attacks are triggered is well understood, but much remains unclear.
● When children with a genetic predisposition to asthma are exposed to triggers, the triggers cause the smooth muscles in the bronchial walls to contract, resulting in abnormal constriction and narrowing of the airways.
● This phenomenon is called bronchoconstriction or airway constriction.
● When an asthma attack is triggered, the bronchi constrict, their walls swell, become inflamed, and mucus is secreted within the bronchi, further narrowing the airways. [Parents Should Become Counterparts – Encyclopedia of Pediatric and Family Nursing] – Volume 8, Respiratory Diseases in Children and Adolescents – Chronic Bronchitis (see
■ Mechanism of Asthma (Bronchial Asthma) Attacks
1. Overall Mechanism of Asthma (Bronchial Asthma) Attacks
▴ Figure 6-1. Cross-sectional and longitudinal views of the airway during an asthma attack.
a-Larynx, b-Trachea, c-Bronchi, d-Bronchioles (Bronchioles), e-Smooth Muscle, f-Alveoli, g-Bronchiole Wall, h-Airborne Secretions (Pustules) (Same as Figure 252)
● Physical exercise or other triggers for asthma attacks can cause airway constriction and partial obstruction.
● In these cases, treatment with bronchodilators can restore normal airway function.
● When an asthma attack is triggered, airway inflammation and airway swelling may occur, but asthma symptoms may be rare or may appear. ● If airway inflammation occurs when an asthma attack has already occurred due to a trigger and then another asthma attack trigger is added, airway inflammation may become more severe, the airway may become more swollen, mucus secretion may increase, and the airway may become more blocked. Used with permission from Hardy 1992
2. Normal Lower Airway and Lungs
Figure 161. a-Larynx, b-Trachea, c-Bronchi, d-Bronchioles
Source: Used with permission from Hardy 1992, and Parents should also be a physician – Pediatric Family Nursing Encyclopedia
3. Normal Airway
Figure 162. Transverse and longitudinal sections of a normal airway:
a-Bronchioles, b-Alveoli
Source: Used with permission from Hardy 1992, and Parents should also be a physician – Pediatric Family Nursing Encyclopedia
4. Airway Constriction Caused by Mild Asthma
Figure 163. ① Transverse and longitudinal sections of a normal bronchiole
② During an attack of mild persistent asthma, the bronchi and bronchioles constrict, narrowing the airway. Source: Used with permission from Hardy 1992 and Parents Should Become Partially Informed – Pediatrics and Family Nursing Encyclopedia
5. Airway Constriction Caused by Severe Asthma
Figure 164. Cross-sectional and longitudinal views of the airway in persistent asthma.
Moderate persistent asthma causes constriction of the bronchi and bronchioles, with phlegm secreted within the airway (top).
Moderate persistent asthma causes severe constriction of the bronchi and bronchioles, with phlegm secreted within the airway, and swelling of the airway walls (bottom).
Source: Used with permission from Hardy 1992 and Parents Should Become Partially Informed – Pediatrics and Family Nursing Encyclopedia
▴ Figures 6-7. Transverse views of the airway during an asthma attack.
③ During a moderate persistent asthma attack, the airways in the bronchi and bronchioles become more constricted, the airway narrows further, and the airway walls become more swollen. ④ When a severe persistent asthma attack is triggered, the airways in the bronchi and bronchioles become more constricted, narrowing the airways and causing the airway walls to swell and become more inflamed.
Source: Used with permission from Paul Sigh Roy. Parents Should Also Become Physicians – Pediatric and Family Nursing Encyclopedia
8. Asthma Attack Mechanism
▴ Figures 6-8. Changes in the airway and cross-sectional views of the airway during an asthma attack.
a- Normal airway (bronchial tube),
b- Acute bronchoconstriction,
c- Chronic asthma causes airway constriction and inflammation of the bronchial walls, further narrowing the airway,
d- Subacute or chronic asthma causes bronchial wall swelling and inflammation, further narrowing the airway.
e- Inflammatory cells,
m- Mast cells release histamine granules. Activation of T cells, B cells, alveolar macrophages, eosinophils, and neutrophils produces various mediators, including histamine, cytokines, leukotrienes, and prostaglandins, which interact to trigger asthma attacks.
MBP: Major basophilic protein (MBP) is secreted, and
PAF: Platelet-activating factor (PAF) is released.
Reference: Asthma, The Pediatric Clinics of North America, December 1992, W. B. Saunders
Copyright drleepediatrics.com 2/22/2026