Asthma Flashcards
What is the definition of asthma
A disease characterised by an increased responsiveness of the trachea and bronchi to various stimuli and manifested by a widespread narrowing of airways & bronchial inflammation, that changes in severity either spontaneously or as a result of therapy; resulting in episodic wheeze and/or cough
What is the two stand out features of asthma
variable and reversible
How is asthma characterised
Wheeze
What are some examples of the multiple triggers
Exercise
Allergen
Cold weather
smoke
perfume
Upper Respiratory Tract (URT) infections,
pets, trees, grass pollen, food, aspirin.
What is the Pathophysiology of asthma
airway inflammation mediated by immune system
What are the proven risk factors of asthma
and other possible risk factors
Genetics
Occupation
Smoking
Possible:
Obesity Diet Reduced microbe exposure (farm children less likely due to previous exposures) Chemical products Environmental exposures Abnormal lungs
What genetic tendency can be inherited that could trigger asthma?
An atopic tendency - which increase IgEs response to allergens
Is it maternal or paternal atopy genetics that is most significant in an IgE to respond to an allergen
What are the two groups of genes that increase atopic tendencies development of asthma
Maternal - epigenetic modification of oocytes
Immune response geneses (IL-4, IL-5, IgE)
Airway response genes (ADAM33)
What is the affects of maternal smoking during pregnancy
Decreases FEV1
Increases airways responsiveness
(therefore increase the risk of asthma/wheezy illness development)
Increases severity
Does environmental exposure directly cause asthma?
No, because the atopy genetics need to be previously present for environmental factors to increase the sensation and trigger asthma
What is the symptoms of asthma
wheezing attacks episodic shortness of breath (dyspnoea) chest tightness cough – paroxysmal(outburst)/ dry sputum (occasional)
What are other examples of airflow obstruction diseases
COPD (irreversible AFO)
bronchiectasis
bronchiolitis
Cystic Fibrosis
What are examples of localised airflow obstructions
inspiratory stridor (obstruction of windpipe)
tumour
foreign body
What are the main areas of concern when diagnosing asthma during a history taking
Past medical history
Current drugs
Family medical history
social medical history
What signs on examination prove its probably not asthma
Clubbing
cervical lymphadenopathy
Stridor (harsh or grating sound)- upper airway obstruction
Asymmetrical expansion
Dull percussion note (lobar collapse or effusion)
Crepitations- crackling/rattling sound (bronchiectasis, CF, alveolitis, LVF)
What are the essential investigations carried out for asthma looking for
Airflow obstruction
Variability and/or reversibility of airflow obstruction