Allergic rhinitis is typically classed as one of three types: seasonal allergic rhinitis (SAR), perennial allergic rhinitis (PAR) or occupational allergic rhinitis.1

These descriptions persist despite attempts in 2001 to significantly revise AR classification by introducing the terms ‘persistent’ and ‘intermittent’ in the ARIA (Allergic Rhinitis and its Impact on Asthma) guidelines. ARIA, an international non-governmental organization, works with the World Health Organization (WHO) through the Global Alliance Against Chronic Respiratory Diseases (GARD).1,2

The revised 2016 ARIA guidelines acknowledge that SAR and PAR remain in common use by health professionals. With few exceptions, research papers use the terms because studies enrol patients by allergen type.1

PAR usage usually reflects indoor allergens created by house dust mites, moulds, and animal dander from cats and dogs (and rodents such as hamsters), as well as pets or companion animals usually kept outside such as rabbits, guinea pigs or horses. Cockroaches can be a significant source of PAR allergens in some countries.1,3

SAR reflects allergy associated with pollen or moulds, usually outdoor, hence it commonly being called hay fever. Common occupational rhinitis allergens include wood dust, flour dust and latex.1,3