FDA warns consumers about topical pain relievers

The agency has received more than 40 reports of skin injuries from over-the-counter products including creams, lotions, ointments and patches. Reported brands included Bengay, Icy Hot, Capzasin, Flexall and Metholatum.

Injuries ranged from mild to severe burns. According to the FDA, in many cases severe burning or blistering occurred within 24 hours of a single application. Some complications required hospitalization.

"There's no way to predict who will have this kind of reaction to a topical pain reliever for muscles and joints,'" said Dr. Jane Filie, a medical officer in the FDA's Division of Nonprescription Regulation Development (DNRD).

FDA chemist Reynold Tan says the burns are associated with products containing the active ingredients menthol, methyl salicylate and capsaicin. Tan says these ingredients create the sensation of coolness or warmth. But they should not burn.

According to the FDA, most of the severe burns came from products containing menthol or a menthol/methyl salicylate combination that had more than 3% menthol or 10% methyl salicylate. Only a few cases involved capsaicin.

Tan says the number of cases is small compared to the number of people who use these products. But the agency has issued the following advice for consumers using these products:

-- don't apply these products to irritated or damaged skin

-- don't apply bandages on top of these products

-- do not apply heat from a heating pad, hot water bottle or lamp to the area where you have applied product - this can increase the risk of serious burns

-- seek medical attention immediately if you experience burning pain or blistering

-- report any unexpected side effects to the FDA MedWatch program