Clinical Features of Asthma in Children Flashcards
what are the challenges of dealing with asthma?
- No definition
- No tests
- Two national guidelines
- Symptom based
- Identical to LRTI symptoms (cough, SOB, noisy breathing)
- Relapse and remission
Tips to dealing with asthma:
- No _________, no asthma
- Tests ___ help decision
- If…..
QoL affected, confirm the diagnosis with trial of ___ (to confirm diagnosis)
QoL not affected (by symptoms), _____ ___ ___
wheeze
may
ICS
watch and see
If child doesn’t wheeze then they don’t have ______
asthma
What is asthma?
- Literally “panting”
- Chronic
- Wheeze, cough and SOB
- Multiple triggers
- Variable/reversible
- Responds to asthma Rx
what 3 things msut you have to have asthma?
•Wheeze, cough and SOB
for asthma you have to have a ________, it has to _______ to treatment and it has to be _______
wheeze
respond
variable
No longer a diagnosis of _________
exclusion
what are the 3 Key words in relation to asthma?
- Wheeze
- Variability
- Respond to treatment
What causes asthma?
No one really knows what causes it
What we know:
- Host response to environment
- Infection important
- Physiology abnormal before symptoms
- It is a syndrome
Many inconsistencies in asthma such as what?
- “Transient” vs persistent (symptoms)
- VIW versus asthma/MTW (multi trigger wheeze)
- Different severities
- Different age at onset
- Heterogeneity in response
- Different triggers
- How can a single condition do this???
Asthma syndromes - can occur in many setting
example picture shown
What causes asthma? - how are genes involved?
- Genes - 30-80% of causation
- ~10 variants making modest contribution
- ADAM33, ORMDL3 (People with these genes don’t all have asthma)
- Interact with environment (If predisposed to asthma, its only when you encounter environment when you get asthma symptoms)
- Epigenetics (the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself)
does allergy cause asthma? - probably not
so what expalines the link between allergy and asthma?
•Primary epithelial abnormality (skin/airway/gut) results in:
- Eczema/asthma/etc
- Allergy
•Allergy then fuels eczema/asthma/etc
Allergic sensitisation fuels the symptoms in the affected organ (skin, lung, gut)
what is the epidemiology of asthma?
a very British problem - Burden of asthma in UK is highest in world (prob same now a days)
- 1.1 million UK children
- 110, 000 in Scotland
- 5% of UK children on inhaled steroids!
Asthma “epidemic” probably over
So why the rise and fall?
Westernisation! - what is it to do with asthma?
Burden of asthma/eczema/hay fever is higher on the western side of these geographically very closely placed areas, these areas where genetic diversity is very limited/very similar so only reason to explain these 2 is lifestyle and/or diagnostic threshold
Western lifestyle is associated with an increased risk of asthma and probably in the first 3 years this is having an influence
- Retained if move >3 yo
- Acquire “Western” risk if born there
what is Proof of causation?
Two RCTs proven causation
Offspring at risk for asthma
Complex
- Feeding - Breast, Late weaning
- Allergen (reduced exposure) - Ante- and post-natal
- Smoking (parents stop)
What happens in _____ life, often before we are born, is a really important ___________ of our later respiratory life course
early
determinant
if they do have asthma like symptoms affecting their QoL then what do you do?
give them a trial of inhaled steroids as a diagnostic test
So when is it asthma? - how do you make the diagnosis?
- All in the history!
- Examination unhelpful - Unlikely to be wheezing, Stethoscope never important (often unhelpful)
- No diagnostic asthma test in children:
- Peak flow random number generator
- Allergy tests irrelevant (Majority of people with allergy don’t have asthma and 25% of people with asthma don’t have allergy)
- Spirometry lacks specificity
- Exhaled nitric oxide unproven
•Tests can be useful (excluding > diagnosing)
how may spirometry be done to be useful?
do it
then make them take a BDR (bronchodilator response)
then repeat and see if it has changed
Asthma diagnosis - NICE
- Spirometry
- BDR
- FeNO
- Peak flow
Asthma diagnosis – BTS/SIGN
- Spirometry
- BDR
- FeNO
- Peak flow
what is the problem with asthma in paediatrics?
- Uncertainty greatest in <5s
- Tests not reliable in <5s
- Tests not great anyway
how is a wheeze present in asthma?
- A “must have”
- But not in isolation
- Cough variant asthma does not exist (in children)
- Cough predominant asthma not uncommon
Is it really wheeze?
- Aberdeen 75% wheeze in two year olds not genuine
- Rattle versus whistle is a good dichotomy
Rattle = bronchitis
Whistle = asthma
Majority will be one of these 2 but mainly rattles
SOB at reast is a importnat feature of asthma - what is it?
- Significant resp difficulty - <30% lung function
- Airway obstruction
- “Sooking” in of ribs with wheeze
cough is a feature of asthma but the problem is:
- Everyone coughs!
- Only 10% have asthma
what isa cough like in asthma?
- Dry
- Nocturnal (just after falling asleep)
- Exertional
what other histories may be helpful?
- Parental Hx asthma (is one parent currently on asthma treatment)
- Personal history
- Eczema
- Hayfever
- Food allergies
a personal history of allergy is circumstantially helpful but the majority of children with eczema, hay fever and food allergies don’t have asthma
What has asthma symptoms and responds to asthma treatment?
- Asthma treatment = ICS for 2 months
- Remember “false positive responses” – holiday (stop inhaler and see if symptoms come back and if they don’t then you have false positive response)
Asthma is a hindsight diagnosis
ideally to make the diagnosis what should be present?
Wheeze (with and without URTI)
SOB@rest
Parental asthma
Responds to treatment
A word about trial of treatment - what is the harm and benefits?
Benefits greatly outweigh harm
My approach to wheeze
So when is it not asthma?
All that is chronic and paediatric and respiratory is not asthma
Simplistically:
- Under 18 months, most likely infection
- Over 5 years, most likely asthma
•BUT if it sounds like asthma and responds to asthma it is asthma regardless of age!
what are Differential diagnosis for “asthma”?
Important to know age of onset when working out differentials
Habitual – no wheeze
Pertussis – LRTI, cough but no wheeze
Asthma vs VIW
My approach to the preschool cough
no wheeze = ???
no asthma
- No _______, no asthma
- Tests ___ help decision
- If…..
I. QoL affected, confirm the diagnosis with trial of ___
II. QoL ___ _______, watch and see
wheeze
may
ICS
not affected
