Asthma

Asthma is an inflammatory disorder of the conducting airways. The airways become hyper-responsive and constrict easily in response to a wide range of exogenous and endogenous stimuli (1).

Asthma is a common chronic respiratory disease affecting 1–18% of the population in different countries.

• associated chronic inflammation leads to hyper-responsive airways which constrict easily in response to a wide range of exogenous and endogenous stimuli leading to recurrent symptoms and variable airflow limitations (1,2)
• symptoms and airflow limitation may settle spontaneously or with medication
  • these episodes may be absent for a long period (weeks or months) at a time (2)

The International Consensus Report on the Diagnosis and Management of Asthma (Global Initiative for Asthma - GINA) has put forward the following definition for asthma:

“Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation. It is defined by the history of respiratory symptoms such as wheeze, shortness of breath, chest tightness and cough that vary over time and in intensity, together with variable expiratory airflow limitation” (2).

Pathologically, there is bronchial inflammation with a prominent eosinophilic infiltrate.

Asthma is common, particularly in developed countries, where up to 10% of children have the disease.

With respect to management of asthma, NICE have stated that (3):

• "...evidence review showed that clinical outcomes were poorest in all age groups with asthma when using SABA (short-acting beta2 agonist) alone...therefore recommended that SABA alone should not be used in people with a diagnosis of asthma..."

References:

1. van der Wiel E et al. Small-airways dysfunction associates with respiratory symptoms and clinical features of asthma: a systematic review. J Allergy Clin Immunol. 2013 Mar;131(3):646-57.
2. Global Initiative For Asthma (GINA) 2023. Global Strategy for Asthma Management and Prevention
3. NICE (November 2024). Asthma: diagnosis, monitoring and chronic asthma management (BTS, NICE, SIGN)