Clinical Question: Is a pollen blocker cream effective in preventing allergic rhinitis?

Setting: Outpatient (specialty)

Study Design: Crossover trial (randomized)

Synopsis: In this study, the authors enrolled 91 white patients in Russia and Germany who had been allergic to house dust mites, animal dander, or pollen for at least two years. The study compared petrolatum with a placebo of carboxymethylcellulose gel, which is aqueous and does not last long. Because this was a crossover study, patients received, in a random fashion, treatment with both products. The patients applied one product four times a day for three days, and then, after one day of no therapy, they used the other product for three days.

Efficacy was assessed with a nasal provocation test using the allergen at a concentration previously demonstrated to elicit symptoms in each patient. Sneezing, nasal discharge, and “other related symptoms” (e.g., tearing, ear itch) each were assigned a value from zero to 2 (maximum score = 6). Scores fell from a median of 4 to a median of 1 following the use of petrolatum; after using placebo, scores fell from a median of 4 to a median of 3 (both statistically significant). Nasal airflow rates were similar between the two treatments. Symptoms were slightly lower with either treatment given in the second three-day phase, perhaps reflecting that, over time, patients became better at applying the products.

Bottom Line: Petrolatum applied four times a day to the nares results in a significant improvement in provoked nasal allergic symptoms. The study was carefully controlled and results may not be the same in practice. Other than an extremely small risk of lipid pneumonia, however, coating the inside of the nose with petrolatum is a nontoxic, non-systemic treatment approach in patients with allergic rhinitis. (Level of Evidence: 2b)