Asthma

Asthma is a chronic inflammatory disorder of the airways. In susceptible individuals, inflammatory symptoms are usually associated with widespread (but variable) airflow obstruction and increased airway response to a variety of stimuli. Asthmatic obstruction is often reversible, either spontaneously or in response to treatment.

WHO estimate that over 300 million people in the world are affected by asthma and it is the most common chronic illness in children. Asthma UK reports a prevalence of 5.4 million in the United Kingdom alone. Asthma can be a distressing and disabling condition for those with poorly managed disease leading to time off work, significant social and psychological impact and hospital admission.

At present, 1,500 people die from asthma each year and many of these deaths might be prevented with adequate routine and emergency care. There are several well-recognised behavioural factors (including smoking and non-compliance to prescribed medications) that will have considerable impact on whether a patient’s asthma will be well-controlled or not. Additionally, poor management of concurrent allergic rhinitis is also recognised as contributory to sub-optimal asthma control.

Asthma is a clinical diagnosis; there is no standardised definition of the type, severity or frequency of asthma symptoms that will be found on investigation. Without a gold standard definition of asthma, evidence-based recommendations for diagnosis are difficult, and without a clear-cut diagnosis, optimal management is challenging.

A working definition of asthma is the presence of airflow obstruction and more than one of the following symptoms:

• Wheezing;
• Breathlessness;
• Chest tightness, and
• Cough

Asthma shares a number of symptoms with other conditions. The non-specific nature of asthma symptoms can lead to a number of possible differential diagnoses at first presentation, such as bronchiectasis, cystic fibrosis (CF), ischemic heart disease (IHD), left ventricular failure (LVF) and, especially in older patients, chronic obstructive pulmonary disease (COPD) (Asthma in Over 65s)

Childhood and adult asthma share many common features, but there are also important differences. For example, age influences the:

• Differential diagnoses (the younger the child, the greater the number of disorders that mimic asthma)
• Natural history of wheezing illnesses;
• Appropriate / possible investigations and their diagnostic value.

• Children: pre-school age
• Children: 5-12 years old
• Adolescents
• Adults
• Adults: over 65 years old