Problematic Severe Asthma in Children – The Pandora’s Box


the less likely is the diagnosis of asthma. A negative bronchial challenge in an allegedly symptomatic child excludes asthma as a cause of those symptoms. Proper investigation should be carried out when the history or physical examination suggests one of the alternative diagnoses, and should be targeted to exclude those specific conditions rather than applied in a blanket fashion to all asthmatics (see Table 2).


Step Two – Is It ‘Asthma Plus’? The next step is the identification of any co-morbidities.27 It should


always be borne in mind that other conditions may coexist with asthma because continuing respiratory symptoms may be wrongly attributed to asthma alone. Some of these are easily identified at the first visit; for example, obesity. Others can be identified at the subsequent assessment.


Asthma Plus – Obesity


and evidence of reversible airway obstruction should be carefully sought before escalation of therapy in the obese. At least in adults, obesity leads to a pauci-inflammatory form of asthma,29 and consideration should be given to non-invasive measurement of airway inflammation before escalating ICS. Finally, obesity is itself a pro-inflammatory state and may cause steroid resistance.30


The relationships between asthma, non-specific respiratory symptoms and obesity are complex. There are several confounding factors, including gastro-oesophageal reflux and the effects of obstructive sleep apnoea. Obesity per se leads to breathlessness that is not related to asthma,28


Asthma Plus – Upper Airway Disease


The relationship between upper and lower airway is hotly debated. Up to 80 % of patients with asthma have rhinitis, and up to 15 % of patients with allergic rhinitis have asthma.31


treat rhinitis increases asthma morbidity.32


There is evidence that neglecting to Therefore the upper airway


should be examined carefully in all asthmatics. Upper airway symptoms may cause significant impairment in quality of life; if by treating upper airway symptoms asthma improves, then this is a significant bonus but one that should not be anticipated. One study has suggested that obstructive sleep apnoea, which is a pro-inflammatory state, may be associated with lower airway neutrophilic inflammation.33 of this to asthma is not clear.


The relevance


Asthma Plus – Dysfunctional Breathing Patterns Many asthmatics also exhibit symptoms of hyperventilation and vocal cord dysfunction, which are only detected if a detailed history is taken. Symptoms that disappear when the child is asleep are very unlikely to be due to asthma.34


Step Three – Assessing Severity and Identifying Contributory Factors


The next step in the protocol is a detailed multidisciplinary assessment to assess the severity of asthma and to identify contributory factors. This is obtained by evaluating the patient with proper testing and by addressing several aspects of asthma education.


Spirometry with measurement of the immediate response to a bronchodilator, assessment of bronchial hyper-responsiveness (by direct or indirect challenges), complete evaluation of allergy (by both skin prick tests and specific immunoglobulin E [IgE] testing [radioallergosorbent test]), and measures of health-related quality of life (by specific questionnaires) should be part of the routine clinical work-up in all children with problematic severe asthma.40


Some of


these assessments will usually have been part of 'Step 1' to question the diagnosis of asthma.


The second component of the work-up addresses the assessment of contributory factors, and it is usually led by an experienced respiratory nurse. If experienced nurses are not available, other personnel should be used, including the family physician. The nurse will typically spend a morning with the family at the hospital, visit the home by arrangement, and make contact with the general practitioner and the child’s school. Several areas are addressed.


Asthma Education Other clues include difficulty


breathing in, throat tightness, paraesthesia, cramps in the hand, and stridor or wheeze loudest over the larynx. In such cases, the aid of a skilled physiotherapist, speech therapist or clinical psychologist should be sought.


Asthma Plus – Gastro-oesophageal Reflux


The relationship between respiratory symptoms and reflux is complex (see Table 3).35


Depending from the criteria used for diagnosis, between


35 % and 80 % of children with chronic respiratory disease have gastro- oesophageal reflux.36


The evidence implicating reflux as causal in severe asthma in children is limited. If asymptomatic reflux is found, treatment is unlikely to ameliorate the symptoms of asthma. If symptomatic reflux is suspected, a therapeutic trial is reasonable, but if there is no response, a pH study is recommended before escalating therapy.37


EUROPEAN RESPIRATORY DISEASE Adherence to Treatment


At the home visit, the nurse will assess whether medications are available or are so inaccessible within the house that they are not being used, or if they are out of date, or even whether empty canisters are being used. Failure to take prescribed medication is the most common reason for continuing symptoms in patients with problematic severe asthma.42


frequently left to take their medication unsupervised,43


Even quite young children are and the extent


93


All children will have been shown how to use their inhalers and been given asthma educational material. In a recent study, nearly 40 % were not using their inhalers correctly despite multiple previous sessions, and nearly 15 % were using an inappropriate device.41 Advice about avoidance of triggers, including allergens, and detection and management of episodes of poor control or acute asthma attacks is also discussed.


Asthma Plus – Food Allergy


Food sensitisation is common in severe asthma. It is often unclear whether this relates to true food allergy. It is also unclear whether both severe asthma and food sensitisation reflect the underlying atopic predisposition or if food allergy is causally related to severe asthma.38,39


Table 3: Relationship between Gastro-oesophageal Reflux and Respiratory Symptoms


Gastro-oesophageal reflux leads to aspiration and symptoms Gastro-oesophageal reflux worsens bronchial hyper-responsiveness via neural activity from the lower oesophagus Respiratory symptoms cause or exacerbate reflux The two co-exist independently


Asthma medication such as theophylline could provoke reflux


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