Health Canada says a safety review has found a risk of serious burns with the use of some over-the-counter topical pain relievers that contain menthol.
These pain relievers are applied to the skin and are intended to help relieve muscle and joint pain. They come in a variety of formulations including creams, gels, liquids and patches.
Health Canada has received 21 reports of serious side-effects involving topical pain relievers containing menthol in various concentrations, either as a single ingredient or in combination with other compounds.
In many cases, the products were used as directed, with burns, severe swelling and blistering appearing within 24 to 48 hours after the first application.
Health Canada says available data did not allow it to determine whether the risk of serious burns is linked to any specific brand, formulation or menthol concentration, or to any ingredient other than menthol.
Consumers who experience serious skin reactions such as pain, swelling or blistering are advised to stop using the product and seek immediate medical attention.
The safety review also looked at the ingredients methyl salicylate and capsaicin. While serious skin burns have been reported with the use of topical pain relievers containing these compounds, the review did not find sufficient evidence to confirm they carry the same risk as menthol.
All topical pain relievers containing menthol, methyl salicylate or capsaicin produce a warming or cooling sensation where they are applied, but they should not cause severe pain or skin damage, Health Canada said in an advisory released Monday.
Even so, some menthol-containing topical pain relievers warn about the risk of serious skin burns on their labels or packaging.
Health Canada will publish an updated labelling standard for all menthol-containing topical pain relievers in the coming weeks to better inform consumers about the risk.