Table 4.

 Types and possible triggers of non‐allergic rhinitis

Type	Suggested triggers/cause	Signs/symptoms
Eosinophilic or non‐allergic rhinitis with eosinophilia syndrome (NARES)	50% develop aspirin sensitive disease with asthma and nasal polyposis later in life [220]	Skin tests negative but nasal smears show eosinophilia Perennial symptoms with paroxysmal episodes. About 50% have bronchial hyper‐reactivity [220]
Autonomic (vasomotor)	Triggered by physical/chemical agents	More common in middle age with clear rhinorrhoea especially in the morning. Less favourable course than allergic. Possibly caused by parasympathetic hyperactivity [221]
Drugs	α‐adrenergic blockers, ACE inhibitors, chlorpromazine Cocaine Nasal decongestants (with prolonged use) Aspirin/NSAIDs	Nasal blockage Rhinorrhoea, crusting, pain and nasal septum perforation reduced olfaction [222] Rhinitis medicamentosa with chronic nasal blockage [126] Acute rhinitis symptoms ± asthma
Hormonal	Pregnancy [157], puberty, HRT, contraceptive pill [223, 224] Possibly hypothyroidism, acromegaly [225, 226]	All can cause nasal blockage and/or rhinorrhoea
Food	Alcohol, spicy foods, pepper, sulphites	Rhinorrhoea, facial flushing Gustatory rhinorrhoea
Atrophic	Klebsiella Ozonae [227] or secondary to trauma, surgery, radiation	Foul‐smelling odour, crusting, hyposmia, nasal blockage [228]
Primary mucus defect	Cystic fibrosis	Children with polyps must be screened for cystic fibrosis [229]
Primary ciliary dyskinesias	Kartagener and Young syndromes	Rhinosinusitis, bronchiectasis and reduced fertility
Systemic/inflammatory	Sjogren, SLE, rheumatoid arthritis, Churg–Strauss [230]	Nasal blockage Polyps, sinusitis, asthma, eosinophilia
Immunodeficiency	Antibody deficiency	Chronic infective sinusitis
Malignancy	Lymphoma, melanoma, squamous cell carcinoma	Bloody, purulent discharge, pain and nasal blockage – symptoms may be unilateral
Granulomatous diseases	Sarcoidosis Wegener's disease [231]	External nasal swelling or collapse, sinusitis, swelling, crusting, bleeding, septal perforation
Structural abnormalities	Nasal septal deviation	Unilateral nasal obstruction unlikely to present unless additional cause, e.g. rhinitis
Idiopathic	Unknown cause – diagnosis of exclusion	May respond to topical capsaicin [232, 233, 234]

ACE, angiotensin‐converting enzyme; HRT, hormone replacement therapy; NSAID, non‐steroidal anti‐inflammatory drugs; SLE, systemic lupus erythematous.