Do products containing menthol exacerbate allergic rhinitis? A narrative review.

The aim of this paper is to review whether products containing menthol exacerbate allergic rhinitis. A literature survey was performed on PubMed, Google and Google Scholar concerning allergic rhinitis (AR). Allergic rhinitis is an inflammatory condition of the nasal mucosa characterized by wheeze, congestion, nasal pruritus and discharge, or any combination thereof. Menthol is a naturally occurring phytochemical, with the formula C10H20O. The L-isomeric form creates the typical odor of peppermints and causes a sensation of coolness when applied to the skin or mucosae. Inhaling menthol vapor is known to affect the respiratory system in a number of different ways. The cooling agent, menthol, is also recognized as a trigger for asthma, AR and urticaria. The menthol molecule stimulates the TRPM8 receptor and may stimulate histamine release in a dose-dependent manner from RBL-2H3 cell cultures. The addition of menthol to products produces symptomatic relief in some patients by providing an impression of freer nasal air flow. It does this by stimulating cold receptors on branches of the fifth cranial nerve. Menthol is capable of provoking allergic hypersensitivity reactions and disorders, including asthma, AR and urticaria. It may also trigger an anaphylactic response. The use of menthol-containing products is best avoided in cases where an allergic disorder exists.