BRONCHIAL ASTHMA

Global Initiative for Asthma (GINA)

defines asthma as a heterogeneous disease, usually characterized by chronic airway inflammation.

asthma

is a lung disease that gets your airways narrowed, swollen, and blocked by excess mucus.

asthma exacerbation

also called asthma flare-up or asthma attack

asthma exacerbation

acute or sub-acute (sudden gradual) worsening in symptoms and lung function, compared with the person’s usual condition

• Wheezing

• Difficulty breathing

• Chest tightness

• Cough

• Trouble sleeping caused by shortness of breath, coughing or wheezing

symptoms of asthma

environmental or genetic factors

Etiology: The root cause of bronchial asthma is unclear; it occurs largely due to

environmental exposures

Research indicates that an individual may inherit a predisposition to asthma, but symptoms are often triggered by ____

• Socioeconomic status

• Family size

• Exposure to secondhand tobacco smoke

• Allergen exposure

• Ambient air pollution

• Urbanization

• Viral respiratory infections

• Decreased exposure to common childhood infectious agents

Environmental risk factors for the development of asthma include:

asthma triggers

any substance that can be breathed in by someone with asthma that can cause asthma symptoms, or make symptoms worse

• dust mites

• pet allergens

• pollen and mould alergens

• cockroach allergens

examples of allergens

• indoor irritants

• outdoor irritants

examples of irritants

allergens

irritants

There are two types of asthma triggers:

being the younger sibling

protective factors: household

birth and nursing

protective factors: natural birth, breastfeeding

• agriculture

• pig/ cattle farming

• unpasteurized milk consumption

• constant stay in animal sheds

• silage

protective factors: farm living

• diverse and healthy microbiota (including of the FLVR groups)

• foodborne pathogens (eg. HAV, H. pylori)

• high burden helminth infections (eg, A. lumbricoides, T. trichuria0

protective factors: microbiological exposures

• better access to doctors/ treatments

• increased education level

• lower stress

protective factors: higher socioeconomic status

• healthy diet

• low pollution rates

• exercise

protective factors: other environmental factors

asthma history in the family

risk factors: household

• caesarian section

• formula feeding

risk factors: birth and nursing

• sheep farming

• pressed or loose hay

risk factors: farm living

• altered dietary practices

• community associated infections

risk factors: urban living

• dysbiotic microbiota

• respiratory viral infections (eg, RV, RSV)

• bacterial pathogens (eg. M. catarrhalis,. S. pneumoniae

• lower burden helminth infections (eg., T. canis)

risk factors: microbiological exposures

• increased smoking rates

• higher stress

risk factors: lower socioeconomic status

• smoking

• obesity

• use of antibiotics

risk factors: other environmental factors

eosinophils

the effector cells most often associated with airway inflammation in asthmatic individuals

mast cells and basophils

may also play an important role in the development of allergic inflammation, through IgE- and chemokine-initiated mediator release.

eosinophilic asthma

is defined as an increase in eosinophils to above 2% or 3%

neutrophilic asthma

as an increase in neutrophils to above 60% or 76% in induced sputum

track 1 (preferred): medium dose ICS- formoterol maintenance and reliever (MART)

track 2: medium dose ICS-LABA+ as needed SABA (or ICS- SABA)

if the patient has daily symptoms or waking at night once a week or more, and low lung function or recent exacerbation

track 1 (preferred): low dose ICS- formoterol maintenance and reliever (MART)

track 2: low dose ICS-LABA + as needed SABA (or ICS- SABA)

if the patient has symptoms most days, or waking at night once a week or more, or low lung function

track 1 (preferred): as needed-only low dose ICS- formoterol (AIR- only)

track 2: - low dose ICS+ as -needed SABA (or ICS- SABA)

• as needed ICS +SABA (separate inhalers or combination)

if the patient has symptoms less than 3-5 days a week, with normal (or mildly reduced) lung function

low-dose ICS

Track 2: In patients with symptoms 1-2 days a week or less, adherence with daily ICS would be very poor , so taking ___ whenever SABA is taken could reduce the risk of exacerbation