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What is asthma?. Guy B. Marks. www.woolcock.org.au. Symptoms. Wheeze, chest tightness, shortness of breath, cough (usually dry) Episodic Triggered Reversible. Diagnostic features. Typical symptoms and episodic nature Airflow obstructive Variable Reversible Inducible
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What is asthma? Guy B. Marks www.woolcock.org.au
Symptoms • Wheeze, chest tightness, shortness of breath, cough (usually dry) • Episodic • Triggered • Reversible
Diagnostic features • Typical symptoms and episodic nature • Airflow obstructive • Variable • Reversible • Inducible • Airway inflammation • Special type of airway inflammation
Major consequences • Distress due to symptoms • Exacerbations • Hospitalisation • Death (rare) • Disability • Impaired quality of life • Adverse effects of treatment
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 airflow obstruction
Associated illnesses • Atopy (allergy) • This, in turn, associated with eczema and allergic rhinitis (hayfever) • Nasal polyps
Causes • Generally not known • Occupational sensitisers cause occupational asthma • Maternal smoking during pregnancy increases risk of childhood wheezing
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
Other triggers – less common • Food additives • Only in some people • Aspirin • Rarely • Other medications
Epidemics • Thunderstorms • Grass pollens • Moulds
80 60 3 40 20 Grains / m 0 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hrs) Wind speed direction Wind Rainfall Wagga Wagga30th October 199712:00 - 24:00
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
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
How common is asthma? ISAAC data reported in The Global Asthma Report, the UNION, 2011
Prevalence of current asthma by age and National Health Survey, Australia Source: National Health Survey
Prevalence of current asthma by socioeconomic status Source: National Health Survey 2007–08
Recent trends in deaths due to asthma by sex, all ages and people aged 5–34 years. Australia Source: AIHW National Mortality Database
Deaths due to COPD and asthma, by sex. Australia Source: AIHW National Mortality Database
The ACAM team Report and slides available at: www.aihw.gov.au and www.asthmamonitoring.org