Table 1.

 Types of non-allergic rhinitis

Type	Causes	Characteristics
Idiopathic rhinitis	Unknown	Rhinitis with sensitivity to strong smells and changes in temperature
Infective rhinitis	Acute or chronic infections	Chronic infection may result from host defence deficiency or a local problem (for example, primary ciliary dyskinesia)
Occupational rhinitis	Organic or chemical agents at place of work	Symptoms are absent during weekends and holidays; affects farmers, laboratory workers, hairdressers, and so on
Non-allergic rhinitis with eosinophilia syndrome (NARES)	Unknown	Nasal eosinophilia; more common in young women
Hormonal rhinitis	Hormonal effects on nasal mucosa and its neurovasculature	Occurs with pregnancy, puberty, hypothyroidism, and acromegaly
Drug induced rhinitis	Systemic drug effects	Common with β blockers, chlorpromazine, oral contraceptives, and aspirin
Food induced rhinitis	Non-allergic reactions to food colourings and preservatives or “IgE hypersensitivity to certain food products”	Rhinitis due to food allergy is always associated with systemic manifestations (such as oral and gastrointestinal symptoms)
Atrophic rhinitis	Primary or secondary to radical surgery, infections, irradiation, or trauma	Nasal crusting and congestion despite having wide nasal passages
Gastro-oesophageal reflux	Direct irritation to nasal mucosa	Particularly affects children