BRONCHIAL ASTHMA (Types, Clinical Features & Treatment)

Bronchial Asthma is a condition in which a person’s airways become narrow and swell to produce extra mucus. This makes it extremely difficult to breathe. 

Bronchial Asthma is one of the essential topics for Padiatrics paper. Read this blog post carefully to ace your NEET PG preparation. 

 What is Bronchial Asthma

It is a chronic inflammatory disorder of airways, characterized by airway hyperresponsiveness, leading to recurrent episodes of reversible airway obstruction causing respiratory symptoms like wheezing, cough, shortness of breath, chest tightness.

Types                                 

• Atopic type: more common
  • Associated with allergic rhinitis, atopic dermatitis
• Non-atopic type: triggered by viral respiratory infections, cold air, exercises

Etiology                         

1. Genetic factors

• Chr 5 : IL4, IL 5, IL 13. Polymorphisms of ADAM 33: proliferation of smooth muscles. Beta 2 adrenergic receptor gene variant. IL 4 receptor gene variant

2. Environment factors

• Hygiene hypothesis: childhood exposure to germs & infections helps the immune system to develop. Dust, animal danders, smoke

3. Prenatal risk factors

• Maternal malnutrition
• Maternal smoking
• Maternal infections
• Stresses
• Use of antibiotics

Triggers            

• Viral resp. Infections. Exposure to animals, dust, molds, pollens. Smoke: challah/incense sticks/tobacco. Air pollutants/aerosols. Drugs: aspirin, beta blockers (cause bronchospasm)

Clinical Features

• Classical symptoms: cough, shortness of breath, wheeze, chest tightness
  • More at night or early morning
  • Triggered by allergens, exercise, cold air
  • Worsened with viral resp. infections
• Severe disease: cyanosis, altered sensorium
• Signs of allergic disease:
  • Skin rashes: eczema, atopic dermatitis
  • Dennie lines: B/L lower eyelid skin folds
  • Allergic salute: nasal crease
  • Allergic shiners: dark circles/ pigmentation under eyes due to congestion of nose & sinuses
  • Mouth breathers: rhinitis with nasal polyps, enlarged adenoids, DNS

Respiratory Examination

• Severe cases:  pulsus paradoxus
• Inspection 
  • Signs of increased work of breathing
  • Hyperinflated chest
  • Tripod positioning
  • Grunting 
  • Inability to speak full sentences
  • Cyanosis
• Percussion
  • Hyperresonant chest
• Auscultation
  • Prolonged expiration with wheezing

Investigations

• Pulmonary function tests (PFTs) or spirometry
  • Possible only in children < 5 yr age
  • Evidence of variable expiratory airflow limitation
  • FEV1/FVC :low(80%)
  • Bronchodilator responsiveness or reversibility: FEV1 increases by 12% of baseline value after inhaling a bronchodilator
  • FEV1 increases by > 12% of predicted after 4 weeks of anti inflammatory therapy
  • Average diurnal variability of PEFR( peak expiratory flow rate) >13%
• Peak expiratory flow meters
  • Portable, hand held, economic devices
  • Used at home for monitoring expiratory airflow obstruction
  • Fall of 20-30% from baseline: impending/ current exacerbation

D/D of bronchial asthma

• Young infants: GERD, aspiration, bronchiolitis
• 6 months to 3 yrs: bronchiolitis, transient wheezers, FB aspiration, CHD
• > 3 years: transient wheeze, CHD

Treatment of asthma in children

• Identify & eliminate exacerbating factors
• Education of patients & parents
• Pharmacological therapy (Reliever & controller)

A&B

• House should be kept clean & dust free
• Wet mopping of floor & other items should be done
• Carpets, curtains, stuffed furniture- should be cleaned periodically
• Adolescent patients & parents to refrain from smoking
• Avoid strong odours: incense sticks, perfumes, wet odour
• To avoid areas that were unoccupied & closed for some days

C. Pharmacological treatment

1. Classify severity
2. Assess risk of exacerbation
3. Select medication
4. Select appropriate device & route
5. Follow up

Classification of asthma severity

Severity	Day time symptoms	Night time symptoms	FEV1	No. of acute exacerbation/ year
Intermittent	< 2/ week	< 2 month	> 85%	≤ 1/year
Mild persistent	> 2/ week but not daily	3 – 4/ month	> 80%	≥ 2/ year
Mod persistent	Daily	> 1/ week	60 – 80%
Severe persistent	Continuous	More frequent	< 60%

Assess risk of exacerbation

• Uncontrolled asthma symptoms
• Medication related: ICS not prescribed, poor technique, poor compliance, high SABA use
• Co- morbidities: obesity, GERD, sinusitis, food allergies
• Exposure to smoke
• Socio economic issues
• Blood/ sputum eosinophilia
• Ever been to ICU or intubated for asthma

Stepwise approach to treatment 

• In each step: avoid/ control triggers. Reliever medication in all steps inhaled beta agonists eg, salbutamol
• Stepwise controller medication
  • Step 1: As per latest GINA (global initiative for asthma, 2019), all patients of asthma should receive ICS, either symptom driven or daily ( because SABA doesn't protect against severe exacerbation & regular/ frequent use of SABA increases risk of exacerbation)
  • Step 2: Daily low dose ICS or daily LTRA
  • Step 3: Daily low dose ICS+LABA or daily LTRA + low dose ICS or medium dose ICS
  • Step 4: Medium dose ICS+ LABA or high ICS or add on ipratropium or LTRA
  • Step 5: High dose ICS +LABA
    • Refer for phenotypic assessment & add on treatment
    • Oral low dose steroid   
• SABA -  Short acting β agonist 
• L – ICS - Low dose inhalational corticosteroid 
• M – ICS - Medium dose inhalational corticosteroid 
• H – ICS - High dose inhalational corticosteroid 

Devices used

a. Metered dose inhaler (MDI)

• Blue: bronchodilator
• Red: steroid

b. MDI + spacer

• Lesser coordination required. Less impaction of drug in oropharynx

c. Using a mask

• MDI + spacer + baby mask: in children < 4 yrs

Follow up

• Assess technique on each visit
• Check for drug compliance
• Check asthma symptoms daily
• Classify into well/ partially/poorly controlled

All are indicative of pediatric asthma except?  A. Increase in FEV1 more than 15% after bronchodilator B. AM:PM variation in FEV1 more than 15% C. FEV1 decreases more than 15% after exercise D. FEV1/ FVC less than 80%

And that is everything you need to know about Bronchial Asthma for Pediatrics preparation. For more informative and interesting posts like this, download the PrepLadder App and keep following our blog.