Clinical Question

Is intranasal capsaicin effective for nonallergic rhinitis?

Evidence-Based Answer

Intranasal capsaicin is safe and effective for reducing symptoms of nonallergic rhinitis (number needed to treat = 4; 95% confidence interval [CI], 1 to 22). There is insufficient evidence to compare the effectiveness of capsaicin to other topical or systemic medications. (Strength of Recommendation: B, based on inconsistent or limited-quality patient-oriented evidence.)

Practice Pointers

Nonallergic rhinitis is a broad term used to describe a heterogeneous group of sinus diseases that are not triggered by aeroallergens.¹ The prevalence of nonallergic rhinitis is 5% to 10% worldwide,² and symptoms include nasal congestion, blockage or obstruction, sneezing, clear rhinorrhea, and nasal itching. Nonallergic rhinitis is diagnosed by exclusion of symptoms related to aeroallergen exposure or infection and anatomic abnormalities through the history and physical examination.³ The authors of this Cochrane review evaluated the effectiveness of intranasal capsaicin in the management of nonallergic rhinitis.

This Cochrane review included two randomized controlled trials (RCTs) and two quasi-RCTs with a total of 302 participants 16 to 65 years of age with nonallergic rhinitis. They all had symptoms lasting at least one hour per day for at least five days during the two weeks preceding the study. Patients with allergic rhinitis, acute or chronic rhinosinusitis, autoimmune rhinitis, or rhinitis related to anatomic abnormalities were excluded. Nasal capsaicin was used in total daily dosages of 42 to 107 mcg given during various treatment periods of three days to four weeks. The primary outcomes were overall symptom scores (global symptom scores, daily record chart score), individual symptom scores (nasal congestion, rhinorrhea, sneezing, nasal itching), and adverse effects. The risk of bias in these studies was low to unclear.

Overall, the results support the use of intranasal capsaicin as an effective way to manage nonallergic rhinitis. In one RCT (n = 24), patients received capsaicin (30 mcg) or placebo every two to three days for a total of seven treatments in two weeks. Capsaicin use improved overall nasal symptoms on a 10-point visual analogue scale during week 2 (mean difference [MD] vs. placebo = −3.34; 95% CI, −5.24 to −1.44); week 12 (MD = −3.73; 95% CI, −5.45 to −2.01); and week 36 (MD = −3.52; 95% CI, −5.55 to −1.48) posttreatment. Another study compared different dosages of capsaicin (1 mcg, 2 mcg, and 4 mcg three times per day for three consecutive days) and showed that at four weeks post-treatment, only the 4-mcg dosage was more effective than placebo for resolution of nasal symptoms (relative risk = 3.17; 95% CI, 1.38 to 7.29).

A third study comparing two treatment regimens of capsaicin (in each regimen the participants used a total of 82.5 mcg) reported that five treatments in one day was more effective in improving rhinorrhea than five treatments every two to three days over two weeks; numerical data were not provided. An RCT of 40 patients showed that although there was no improvement in individual symptom score with capsaicin in a dosage of 10.5 mcg once weekly for four weeks vs. intranasal budesonide (Rhinocort), capsaicin use did improve aggregate symptom relief scores at four weeks on a 10-point visual analogue scale (MD = 2.50; 95% CI, 1.06 to 3.94). Study heterogeneity precluded meta-analysis.

Only one study measured adverse effects. These included nasal blockage, itching, sneezing, and coughing, which are also symptoms of nonallergic rhinitis. Because the study did not clarify when these symptoms were measured, no definitive conclusions could be drawn. Intranasal capsaicin has been reported to cause burning, lacrimation, rhinorrhea, and cough.⁴

Capsaicin is available over the counter as an inexpensive nasal spray. Clinical guidelines from the National Asthma Council Australia and The British Society for Allergy and Clinical Immunology support the use of capsaicin for nonallergic rhinitis as a complementary treatment.^5,6

SOURCE: GevorgyanASegboerCGorissenRvan DrunenCMFokkensWCapsaicin for non-allergic rhinitis. Cochrane Database Syst Rev2015;(7):CD010591.

The practice recommendations in this activity are available at http://summaries.cochrane.org/CD010591.