types of asthma

Asthma has been classified according to recognizable clusters of demographics, clinical and/or patophysiological characteristics (phenotypes). However there is no standardized method or agreed-upon classification system to define asthma phenotypes.
Several phenotypes have been described. Some of the most common types include:

• allergic asthma
• most easily recognised type
• majority begins in childhood
• associated  with past and/or family history of allergic disease such as eczema, allergic rhinitis, or food or drug allergy
• usually respond well to inhaled corticosteroid (ICS) treatment
• non-allergic asthma
• not associated with allergy
• sputum may contain neutrophils, eosinophils or only a few inflammatory cells
• often respond less well to ICS
• late-onset asthma
• onset of asthma is in adult life, particularly in women
• tend to be non-allergic
• higher doses of ICS are often required, some are relatively refractory to corticosteroid treatment
• asthma with fixed airflow limitations
• seen in patients with long standing asthma
• thought to be caused by airway remodelling
• asthma with obesity
• some obese asthmatic people suffer with prominent respiratory symptoms with little eosinophilic airway inflammation (1)

These phenotypic clusters help in identifying different subtypes of asthmatic patients. However clustering has not yet led to differential treatment strategies (2). 

Reference:

• (1) Global Initiative For Asthma (GINA) 2016. Global strategy for asthma management and prevention
• (2) Olin JT, Wechsler ME. Asthma: pathogenesis and novel drugs for treatment. BMJ. 2014;349:g5517.