Asthma Clinical Features, Adults and Children Flashcards
What is asthma characterised by?
Increased responsiveness of trachea and bronchi to various stimuli and manifested by widespread narrowing of airways.
How can asthma change in severity?
Spontaneously or as a result of therapy
What causes the airways to become inflamed?
The immune system
What does the increased airway reactivity cause?
Airway narrowing - resulting spontaneously or from stimuli
What is the prevalence of asthma?
Children 10 - 15% M > F
Adults 5 - 10% F > M
What are the genetic risk factors for asthma?
Atopy
- Inherited tendency to IgE response to allergens
Asthma, eczema, hayfever, food allergy Markers, skin prick tests, IgE
Strongest risk factor: personal, familial atopic tendency - Maternal atopy most influential (3x father)
What allergens can occupation expose you to?
Isocyanates (paints)
Colophony (welding solder flux)
Laboratry Animals
Grains
Enzymes
Drugs
Crustaceans
What are the symptoms of Asthma?
Wheeze Shortness of breath Chest tightness Cough paroxysmal, usually dry Sputum
What are typical triggers?
Exercise, cold air, smoke, perfume, URTI’s, pets, tree, grass pollen, food, aspirin
What type of variation in asthma might help determine the trigger?
Daily Weekly - Occupation, weekends? Holidays? Annual Variation (environmental allergens)
What are essential investigation for asthma diagnosis?
Airflow obstruction Variability and reversibility of airflow obstruction
What is the effect of maternal smoking on FEV1?
FEV1 ia reduced
What is the effect of maternal smoking on Wheezy illness, airway responsiveness, asthma and severity?
All increase
What is known as the Grandmother effect?
Grandchildren are far more likely to suffer from asthma if their grandmothers smoked while pregnant.
Mouse work suggests epigenetic modification of oöcytes
What are the three proven risk factors?
Smoking, genetic and occupation
What are possible risk factors for asthma?
Obesity, diet, reduced exposure to microbes/microbial products, indoor pollution, environmental allergens (house dust mite, cat, grass pollen)
What is body mass index positively associated with?
Asthma
Wheezing
Airway hyperactivity
Which diet substances affect risk of asthma?
Decrease in anti oxidants and N-3 polyunsaturated fatty acids = risk factor
Increase in N-6 polyunsaturated fatty aids = risk factor
Too much or too little vitamin D
Where might a child be born who has a smaller risk of developing asthma?
Farms - increased exposure to microbes and microbial products on the farm
Give an example of microbial products
Endotoxin, glucans, extrascapular polysaccharide
Microbial diversity also important in redusing risk of asthma and allergy
Which indoor cleaning products have an increased risk of causing cancer?
Volatile organic compounds
Formaldehyde
Fragrances