what is asthma (dr. guy marks)

8/2/2019 What is Asthma (Dr. Guy Marks)

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What is asthma?

Guy B. Marks

www.woolcock.org.au


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Symptoms

Wheeze, chest tightness, shortness of

breath, cough (usually dry)

Episodic Triggered

Reversible


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Diagnostic features

Typical symptoms and episodic nature

Airflow obstructive

Variable Reversible

Inducible

Airway inflammation Special type of airway inflammation


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Major consequences

Distress due to symptoms

Exacerbations

Hospitalisation Death (rare)

Disability

Impaired quality of life

Adverse effects of treatment


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Life Course

May start at any age

Typically, in childhood

Childhood asthma may remit

Typically, if mild and not associated with allergy

Asthma persisting into adulthood rarely remits

May wax and wane during life

Some cases progress to chronic airflowobstruction


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Associated illnesses

Atopy (allergy)

This, in turn, associated with eczema and

allergic rhinitis (hayfever)

Nasal polyps


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Causes

Generally not known

Occupational sensitisers cause occupational

asthma Maternal smoking during pregnancy

increases risk of childhood wheezing


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Triggers and exacerbating factors

Viral respiratory tract infections

Most commonly, the common cold

Also influenza, RSV, others

Allergens, if sensitised

HDM, grasses, animal danders, moulds

Occupational sensitisers

Exercise, laughter, rapid breathing (anxiety) Irritants

Insect sprays, perfumes, cigarette smoke


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Other triggers less common

Food additives

Only in some people

Aspirin Rarely

Other medications


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Epidemics

Thunderstorms

Grass pollens

Moulds


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30/31 October 1997, Wagga

ED attendances for asthma 215

Hospital admissions for asthma 41

Intubated in ICU 2


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12 13 14 15 16 17 18 19 20 21 22 23 24

Grains/m

3

0

20

40

60

80

Wind

speed

Wind

direction

Rainfall

Time (hrs)

Wagga Wagga

30th October 1997

12:00 - 24:00


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Variation in asthma

Age of onset and life course

Severity and prognosis

Type of inflammation

Association with allergy

Response to treatments

Triggers and exacerbating factors


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Treatment for asthma

Suppress inflammation

Steroids

Other non-steroid agents that target components of the

inflammatory response

Relax airway smooth muscle and allow airways to

open

Short-term, rapid onset

Longer-term (12-24 hours)

Various methods of delivery


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How common is asthma?

ISAAC data reported in The Global Asthma Report, the UNION, 2011


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Prevalence of current asthma by age and


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Prevalence of current asthma by age andNational Health Survey, Australia

Source: National Health Survey

P l f h b i i


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Prevalence of current asthma by socioeconomic status

Source: National Health Survey 200708

Recent trends in deaths due to asthma by sex


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Recent trends in deaths due to asthma by sex,all ages and people aged 534 years. Australia

Source: AIHW National Mortality Database


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Deaths due to COPD and asthma, by sex.Australia

Source: AIHW National Mortality Database


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The ACAM team

Report and slides available at: www.aihw.gov.au and www.asthmamonitoring.org
http://www.aihw.gov.au/http://www.asthmamonitoring.org/http://www.asthmamonitoring.org/http://www.aihw.gov.au/

what is asthma (dr. guy marks)

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