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Joint Collaborative Severe Asthma Service
2019-01-07
The prevalence of asthma in Hong Kong is around 10%. Mortality (c. 100/year) has not changed in 10 years or more and about 25% of asthma deaths are less than 65 years old. Compared to 2003 – 2008, the median annual asthma hospitalisation rate per 100,000 population has increased by about 15% from 2009 to 2013. It suggests that while the numbers of asthmatic patients remain about the same, the disease(s) is becoming more severe.
Difficult-to-Manage and Severe Asthma
It is estimated that difficult-to-manage asthma comprises about 20% of all asthmatics, whereas severe asthma comprises about 4% of the asthmatic population.
Difficult-to-manage asthma is defined as severe symptoms as a result of non-compliance with medicines; and those who struggle with co-morbidities, such as severe rhinitis, obesity.
Patients with severe asthma have severe symptoms despite taking optimal treatment and their co-morbidities being effectively managed. Most of them will be using long-term oral steroids, which have serious side effects and should be avoided if possible.
Asthma UK has estimated that the 4% of patients with severe asthma use 85% of the total healthcare resources devoted to asthma in the UK. It seems likely that similar figures pertain to Hong Kong.
International guidelines recommend that asthmatic patients should be referred to a specialist if they need more than two courses of steroids within 12 months and/or they are in the difficult-to-manage and severe ends of the asthmatic spectrum. Specialist asthma services often have the tools and experience that are not usually available to non-specialists or primary care physicians to manage asthmatic patients, and severe asthma clinics/services are even more specialised. Our Centre ‘s Director was previously the head of a severe asthma clinic in the UK.
Our Services
Severe Asthma Programme
Our severe asthma service focusses on the unmet clinical need of the most severe end of the asthmatic spectrum, i.e. 4% of the asthmatic population.
Difficult-to-Manage and Severe Asthma
It is estimated that difficult-to-manage asthma comprises about 20% of all asthmatics, whereas severe asthma comprises about 4% of the asthmatic population.
Difficult-to-manage asthma is defined as severe symptoms as a result of non-compliance with medicines; and those who struggle with co-morbidities, such as severe rhinitis, obesity.
Patients with severe asthma have severe symptoms despite taking optimal treatment and their co-morbidities being effectively managed. Most of them will be using long-term oral steroids, which have serious side effects and should be avoided if possible.
Asthma UK has estimated that the 4% of patients with severe asthma use 85% of the total healthcare resources devoted to asthma in the UK. It seems likely that similar figures pertain to Hong Kong.
International guidelines recommend that asthmatic patients should be referred to a specialist if they need more than two courses of steroids within 12 months and/or they are in the difficult-to-manage and severe ends of the asthmatic spectrum. Specialist asthma services often have the tools and experience that are not usually available to non-specialists or primary care physicians to manage asthmatic patients, and severe asthma clinics/services are even more specialised. Our Centre ‘s Director was previously the head of a severe asthma clinic in the UK.
Our Services
Severe Asthma Programme
Our severe asthma service focusses on the unmet clinical need of the most severe end of the asthmatic spectrum, i.e. 4% of the asthmatic population.
- Multidisciplinary Team Approach
The new collaborative team comprises Specialists in Allergy and Immunology, Adult Respiratory Medicine, Paediatric Respirology as well as dietitians and specialist nurses. As the first of its kind in Hong Kong, the collaboration aims to provide synergy without sacrificing independence.
The team comprises:
• Specialist in Allergy and Immunology
• Specialist in Paediatric Immunology & Infectious Diseases
• Specialist in Paediatric Respirology
• Specialists in Respiratory Medicine
• Dietitian
Severe asthmatic patients can be referred to any member of the team, who will assess each patient for suitability to join the severe asthma programme. - Comprehensive Diagnostic Tests
Asthma is not one disease and precise definition of the phenotype and endotype for each patient is essential to optimise personalised treatment. The Allergy Centre of HKSH already has in place a comprehensive suite of diagnostic tests that include detailed lung function tests; mannitol and methacholine inhalation tests; fractional expired nitric oxide; induced sputum tests; nasendoscopy; bronchoscopy (Respiratory Centre); skin and blood tests to identify allergies; dedicated facilities for nasal, conjunctival and oral allergen challenges; exclusion diets to identify and treat food triggers. Other tests are being developed. - New Treatment Strategies
Decades of fundamental and translational science have resulted in a better understanding of the cytokine cascades that contribute to severe asthma, and new specific drugs to target these pathways have been developed.
These strategies include allergen-specific desensitisation based on the precise definition of an individual’s allergen sensitivities using molecular allergology, and new drugs are available to target precise mechanistic pathways.
The drugs include those that are directed to down-regulating IgE, such as omalizumab and dupilumab, and anti-eosinophilic drugs, such as mepolizumab, reslizumab and benralizumab. In addition, long-acting muscarinic antagonists, such as tiotropium, have been approved for use in severe asthma. Bronchial thermoplasty is also being used to treat severe asthmatic patients with substantial airways obstruction through reduction of smooth muscle mass.
Most of the drugs indicated above are monoclonal antibodies. The Allergy Centre is experienced in the use of these and similar drugs. Bronchial thermoplasty is also well established in the Respiratory Medicine Centre of HKSH.
