It is a very good idea to focus on this problem at a time when the heterogeneity of asthma is well recognised. The book comprises 33 chapters, divided into 11 diff erent sections, covering this important topic, all of which are written by experts in the fi eld. All these factors may aff ect asthma diagnosis, control and, perhaps, phenotypes and future risks. Overall, this book highlights the need to consider a step-by-step assessment of these factors in patients with asthma.
The complexity of the interrelationship between asthma and the comorbid or coexisting condition is one of the current major challenges in asthma. The main issue is to correctly defi ne the comorbidity, the coexisting conditions or a diff erential diagnosis. Thus, it is surprising that the term “diffi cult asthma” is not used in this book. This terminology covers asthma that is uncontrolled, despite the best available management. From this starting point, the physician should secure the diagnosis (diff erential diagnosis), and then assess the compliance to treatment. The next step should focus on comorbid conditions and coexisting conditions and their potential to interfere with the best disease control. At the end of a long follow-up period, investigations will result in the potential term “severe asthma”.
In the present book I was very interested by the chapters dealing with unmet and future research needs. However, I was disappointed by the choice of some of the chapters when their impact on the initial problem was not obvious. Asthma in the elderly or during pregnancy is difficult to integrate into the scope of the present book, and may represent a question by themselves. Th ey do not contribute to any of the current main issues of asthma and comorbidity.
In addition, some of the chapters were not related to the title. Hypersensitivity pneumonitis is very appealing in this context when you know that some investigators have found granulomatous tissue in open lung biopsies of severe asthmatic patients. Overall, this chapter represents a state-of-the-art view on hypersensitivity pneumonitis and does not question the potential relationships between asthma and hypersensitivity pneumonitis.
Concerning vasculitis, once again the reader is waiting for a clear signal that is it severe asthma. Or is it a diff erent disease with a specifi c natural history? The recent use of anti-interleukin-5 strategies in severe asthma is mentioned, but their potential role in better understanding and dismantling these complex syndromes is not discussed. It is interesting to conclude that anti-neutrophil cytoplasmic antibodies, which are mentioned in a chapter title, might be absent in most of these clinically undistinguishable conditions. Allergic bronchopulmonary aspergillosis is another very good example of a specific phenotype of asthma. I was puzzled because allergic bronchopulmonary aspergillosis can occur in cystic fi brosis and the specifi city of the relationship with asthma is not clear. Immune defi ciencies do not impact on the diagnosis and management of asthma and appear as an epiphenomenon in this context.
In the chapter devoted to the lung, one may consider sleep apnoea in children and adults as a true comorbid condition with a specific diagnosis. The link with obesity and the need to investigate sleep in difficult asthma is obvious. The chapter on chronic obstructive pulmonary disease (COPD) is likely to convince the reader to reconsider chronic airway disorders and fi nd a new way to study these entities. Permanent airflow obstruction and bronchodilator reversibility are not the best way to make a real diagnosis in asthmatic smokers or asthmatics with nonreversible obstruction. Bronchiectasis is common in most airway diseases, thus, this chapter is of limited help to better understand the mechanisms leading to these major structural changes in the bronchi in asthma.
The chapters on bronchiolitis and pneumonias are interesting but do not have a place in this book as they represent acute infectious diseases and their real impact on inception and chronicity of asthma are still a matter of debate. Cardiovascular diseases are comorbid conditions in asthma less frequently than in COPD. The percentage of patients with both diseases may increase with age, with a focus on severe asthma. The role of the paediatric cardiologist is to differentiate asthma from a persistent cardiac insuffi ciency. Pulmonary hypertension is clearly a differential diagnosis and requires appropriate diagnosis and treatment. The “Upper/Extrathoracic Airway” section is not helpful in better understanding the situation. It is hard to understand the way to differentiate allergic rhinitis from other rhinosinusitis with or without polyposis. As mentioned previously, there is a large body of evidence linking the nose and asthma but clear data showing its real impact on asthma control and severity are still lacking. Most data are obtained from patients complaining of symptoms, thus, one can imagine that the perception varies among the patient population, indicating a more objective way to ascertain this diagnosis. Real vocal cord dysfunction is a rare disease with a complex management. A specifi c diagnosis is possible and a specifi c therapeutic approach should be evaluated. Th e relationship between gastro-oesophageal refl ux disease and asthma is not well understood, despite the large amount of available data and randomised controlled studies. Overall, gastro-oesophageal refl ux disease is a comorbid condition and should be treated as such. The benefit on asthma control or specific symptoms, such as cough, is difficult to predict. The real impact of obesity and subsequent complications on asthma remains to be determined. Endocrine disorders and even low vitamin D levels have been associated with asthma. Severe asthma is also more frequent in females. However, most of the findings are descriptive and no single hormonal interventions have been successful in changing the natural history of the disease. Osteoporosis is clearly a comorbid condition linked to asthma due to the use of glucocorticosteroids. It can be anticipated by early treatment intervention but the role of asthma per se is unclear.
Overall, this book represents an interesting advance to better understand the relationships between asthma and other chronic conditions. I enjoyed reading some of the chapters, however, some were not directly related to the title which is a pity. This book would be of interest to junior physicians in this fi eld as an introduction to the topic. It will certainly stimulate discussions between senior physicians and scientists in the field of asthma.
- ©ERS 2014
