Diagnosis of asthma – a new approach

Abstract

Current definition of asthma involves four cornerstones: inflammation, hyperresponsiveness, bronchoconstriction, and symptoms. In research, the symptoms have had the slightest attention. According to international guidelines, the asthma symptoms are episodic breathlessness, wheeze, cough, tightness of the chest, and shortness of breath. As there are several symptoms, a primary question is how they are related to bronchoconstriction, the main clinical feature of asthma. Symptoms and lung function tests are regularly used for the evaluation of clinical health status and effect of treatment. However, there is no or poor correlation between these two variables, which means that they represent different mechanisms. Reduced lung function, such as a low FEV 1 , represents bronchial constriction, what do the symptoms represent? Some symptoms such as breathlessness and shortness of breath seem not to be evidence-based asthma symptoms. Focusing on bronchial obstruction is important in view of the potential risk of asthma attacks, but nonobstructive symptoms occur frequently and may also cause severe discomfort and poor quality of life. Interpreting all symptoms as signs of bronchoconstriction (asthma) may lead to misinterpretation when assessing health status and effect of treatment. Although a 'soft' variable, the strength of symptoms is that they are representing various mechanisms. The physiological preconditions for control and defense of respiration must be considered in the diagnostic process, regardless of inflammation, allergy, psychology, or other etiological factors. Based on studies on dyspnea in cardiopulmonary diseases, including asthma and asthma-like disorders, there seems to be a continuous spectrum of symptoms and mechanisms integrated in a single asthma syndrome.

Asthma During Pregnancy and Clinical Outcomes in Offspring: A National Cohort Study

“…One limitation is that we did not have information on asthma severity, including duration of asthma episodes, even though it could be hypothesized that the magnitude of disease risk may be lower in offspring of mothers with less severe asthma during pregnancy. 4,68 Moreover, we were not able to operationalize asthma according to a specific definition (eg, taking into account key characteristics, such as inflammation, hyperresponsiveness, reversible airway obstruction, and respiratory symptoms 17,18 ), as the required information, including diagnostic test results or information on asthma subtypes, was not available from the interviews, and it is hardly feasible in a large cohort to assess such details. However, validation of self-reported asthma against physician diagnoses, 19 together with the high percentage of women with asthma during pregnancy and a doctor-diagnosis of lifetime asthma in this study, allows to at least approach the definition of asthma according to the ICD-10.…”

“…A mother was considered to have asthma during pregnancy if self-reported asthma of any type had occurred at any time during the current pregnancy, without further specification according to previously suggested asthma definitions. 17,18 Women were asked if they had a lifetime history of asthma, if a doctor had diagnosed the asthma, and if they were suffering/had suffered from asthma during pregnancy. The agreement of case ascertainment by patient self-report and physician diagnosis has been shown to be high (k: 0.83), 19 and additional analysis of the study cohort revealed that 95.85% of women reporting lifetime asthma had received this diagnosis by a doctor.…”

Medical emergencies: pulmonary embolism and acute severe asthma

“…All too often, asthma is used as a synonym of dyspnoea [51]. Indeed, so heterogeneous are the phenotypes of what can be referred to as asthma that there have been calls to abandon the use of the term altogether [52].…”

Diagnosis of asthma – new theories

“…27-29, 31, 32, 34-55 Follow-up studies have shown that physician-diagnosed asthma cannot be verified in up to one third of patients investigated. [56][57][58][59][60] As many of these non-asthma patients still have symptoms other non-obstructive mechanisms must exist. 60 The high proportion of treatment failure and misdiagnosis may justify the testing of new theories.…”