Intranasal capsaicin
Intranasal capsaicin, a TRPV1 (transient receptor potential vanilloid subfamily, member 1) agonist, has been found to be effective in the treatment of NAR or patients with a significant component of NAR.[43]Gevorgyan A, Segboer C, Gorissen R, et al. Capsaicin for non-allergic rhinitis. Cochrane Database Syst Rev. 2015 Jul 14;(7):CD010591.
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010591.pub2/full
http://www.ncbi.nlm.nih.gov/pubmed/26171907?tool=bestpractice.com
This suggests a role for TRP receptors in this disorder.[12]Bernstein JA, Davis BP, Picard JK, et al. A randomized, double-blind, parallel trial comparing capsaicin nasal spray with placebo in subjects with a significant component of nonallergic rhinitis. Ann Allergy Asthma Immunol. 2011 Aug;107(2):171-8.
http://www.ncbi.nlm.nih.gov/pubmed/21802026?tool=bestpractice.com
[44]Van Gerven L, Alpizar YA, Wouters MM, et al. Capsaicin treatment reduces nasal hyperreactivity and transient receptor potential cation channel subfamily V, receptor 1 (TRPV1) overexpression in patients with idiopathic rhinitis. J Allergy Clin Immunol. 2014 May;133(5):1332-9, 1339.
http://www.ncbi.nlm.nih.gov/pubmed/24139494?tool=bestpractice.com
A Cochrane review concluded that capsaicin is a reasonable option to try under physician supervision, particularly as there are so few options in non-allergic rhinitis.[43]Gevorgyan A, Segboer C, Gorissen R, et al. Capsaicin for non-allergic rhinitis. Cochrane Database Syst Rev. 2015 Jul 14;(7):CD010591.
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010591.pub2/full
http://www.ncbi.nlm.nih.gov/pubmed/26171907?tool=bestpractice.com
When given under physician supervision, capsaicin is administered under local anesthesia, as the concentration of capsaicin used causes a great deal of irritation.[12]Bernstein JA, Davis BP, Picard JK, et al. A randomized, double-blind, parallel trial comparing capsaicin nasal spray with placebo in subjects with a significant component of nonallergic rhinitis. Ann Allergy Asthma Immunol. 2011 Aug;107(2):171-8.
http://www.ncbi.nlm.nih.gov/pubmed/21802026?tool=bestpractice.com
Homeopathic preparations are also available, which include capsaicin and also other ingredients such as eucalyptus and menthol, both of which can also activate TRP receptors. Since they are available in nasal sprays, these can be used by patients without direct supervision, but they are not considered true capsaicin, due to the additional ingredients.
Botulinum toxin
Botulinum toxin type A is a potential treatment option for chronic rhinitis patients who are resistant to other treatments.[45]Rinzin K, Hoang MP, Seresirikachorn K, et al. Botulinum toxin for chronic rhinitis: a systematic review and meta-analysis. Int Forum Allergy Rhinol. 2021 Nov;11(11):1538-48.
http://www.ncbi.nlm.nih.gov/pubmed/33956405?tool=bestpractice.com
[46]Mansour OI, Hamdy TA, Abdelhamid AN, et al. Role of botulinum toxin injection in non allergic non infectious chronic rhinosinusitis (a systematic review). QJM. 2020 Mar;113 (Suppl).
https://academic.oup.com/qjmed/article/113/Supplement_1/hcaa047.021/5829045
Controversial therapies
Currently unproven treatment modalities for non-allergic rhinitis include radiofrequency stimulation and kinetic oscillation stimulation.[47]Juto JE, Axelsson M. Kinetic oscillation stimulation as treatment of non-allergic rhinitis: an RCT study. Acta Otolaryngol. 2014 May;134(5):506-12.
http://www.tandfonline.com/doi/full/10.3109/00016489.2013.861927
http://www.ncbi.nlm.nih.gov/pubmed/24580125?tool=bestpractice.com
[48]Deenadayal DS, Kumar MN, Sudhakshin P, et al. Radiofrequency reduction of inferior turbinates in allergic and non allergic rhinitis. Indian J Otolaryngol Head Neck Surg. 2014 Jan;66(Suppl 1):231-6.
http://www.ncbi.nlm.nih.gov/pubmed/24533389?tool=bestpractice.com
[49]Petersen NB, Larsen K. Kinetic oscillation stimulation of nasal mucosa as treatment for non-allergic rhinitis. a pilot study. Acta Otolaryngol. 2021 Jan;3(1).
https://actascientific.com/ASOL/pdf/ASOL-03-0161.pdf
[50]Stolovitzky JP, Ow RA, Silvers SL, et al. Effect of radiofrequency neurolysis on the symptoms of chronic rhinitis: a randomized controlled trial. OTO Open. 2021 Jul-Sep;5(3).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8436321
http://www.ncbi.nlm.nih.gov/pubmed/34527852?tool=bestpractice.com